Most survivors will just show up at camp or the sheriff will find them and you'll have to meet him alone but some will only show up on specific missions. this is based on where i have encountered them so one may show up somewhere i didn't list. if you fail any of their mission they mostly go inactive for 2-3 days but some will die if you blow off the mission.

Jamal: he normally just shows up at camp and gives 2 missions. note: he dies if you fail either mission.
Mission 1: kill 3 dear in the forest (day).
Mission 2: Find his wife zone 14 of the city(day) .

Larissa: Larissa, Mary, or Liz will shows up on the first sheriff mission and she gives 1 mission.
Mission: meet her in the camp area then she want to go to the forest (day). NOTE: if you don't go to the camp that day she will get killed by zombies also she may still die if you don't do the mission or at lest go to the area then leave.

Bill: he always just shows up at camp and will give 2 mission
mission 1: loot 3 cars on the highway (day). note: if you try to go on after you loot 3 cars he will go back to camp and you will not be able to use him for 2-3 days.
mission 2: loot 3 cars on the highway (night). note: on at 3rd car he will want to go back if you do you'll fail the mission but if you don't he will go back to camp leaving you to fight a wave of zombies 1 man short and you will not be able to use him for 2-3 days when you get back to camp.

Terance: he joins you when your forced to fight 10 areas alone in the desert and gives a 2 part mission that can lead to 3 of the endings.
mission: he asks you to go to area 15 and then 20 of the desert (in the same run). if you fail to get to area 15 you'll get failed ending 3. if you get there and depending on if you went to area 20 and also depending if you defeated the punks you'll get 1 of 3 successful ending. note: your health will be healed after area 15 if you go on.

James: save him on the highway (night) when you get the 2 rescue missions and he will give you 1 mission if you don't have Jennifer.
mission: save Jennifer ?city/highway? {?night?}

Jennifer: she can just show up at camp and will give 2 missions
mission 1: kill a general in area 20 of the highway (day)
mission 2: late game she gives you a mission to kill Dexter in area 20 of the city (night). note: this leads to what one of the 3 successful endings you can get.

Liz: Larissa, Mary, or Liz will shows up on the first sheriff mission, she can show up at camp, or Mary, or Liz will be on one of the two rescue mission. she is in the forest (night) and adds 1 mission but is part of another.
mission 1: Reach area 20 in the woods (day) and you'll get a really nice ak-47-2 but she will want to keep it but you can take it from her at any time. note: this mission is not timed.
mission 2: later after she gets into a fight with Trish you'll need to ask someone to leave. picking anyone but liz will fail that mission. note: being nice to her will not stop this and you lose all items on the person you kick.

Mary: Larissa, Mary, or Liz will shows up on the first sheriff mission, or Mary, or Liz will be on one of the two rescue mission, she is in the woods (night) and adds 1 mission.
mission: you'll need to get her meds in the ?forest? (?night?) or she dies.

Hank: he will show up at camp hurt and will need a med kit (find or craft it and i'm not sure what happens if you fail this but i'm thinking death) or you'll have a chance to get him during Lydias mission. he will give you a mission if you don't have Lydia.
mission: look for Lydia on the highway (?day?).

Lydia: shows up at camp or found from Hanks mission and she has 1 mission.
mission: meet her in the camp area then she want to go to area 10 of the highway (day). if you don't have Hank you can get him before area 10 if you can convince Lydia to go. NOTE: if you don't go to the camp that day she will get killed by zombies also she may still die if you don't do the mission or at lest go to the area then leave and yes you can get Hank and finish the mission.

Mason: you'll get him during a mission to meet the sheriff alone in area 4 i think of the city (day) and he gives 1 mission.
Mission: find Sharon in area 10 in the city (night).

Sharon: she joins from Mason's mission and has no mission for you.

other missions
1)build a random weapon. you must craft the weapon Trish wants and you can not find it to complete this. note: this mission is not timed.
2-5) you'll get 2 kill X of Y zombie and kill x of y punk to lower attacks by said zombie/punk. if you miss them you'll get attacked more and have more waves to deal with (max 3 waves). i'm not sure if you only get 4 . [missions include = destroy 3 punk outposts city (night)]
6-7) you'll also get 2 missions to meat the sheriff somewhere and if you miss these you'll miss out on a survivor. the first one i think you'll get Mary, Liz or Larissa (this maybe the only time you can get Larissa also i think this one happens in the camp or on the highway i forget who i got from them) and the 2nd is always Mason in the city (day).
8) about day 10 you'll be asked to repair a radio tower. you'll need all the materials the day before the last day of completion or you'll fail. if you fail you'll get failed ending 1.
9) you'll get a mission near the end to clear a tunnel you'll need the materials the day before the last day of completion or you'll fail. if you fail your game will end 10 days later. i think you'll get failed ending 3. note: when you do this mission it goes into a 4 area lone fight then 6 more areas with Terance.
10) you'll get a mission on day 32 to take Jennifer, Larissa, Lydia or a chance to skip it to go to area 10 on the highway (day) with only you and them.

merchant
he ask you to sell him 2 random items throughout the game. they can be found or made. if you don't you will not get anymore missions from him and i'm not sure if it effect what items he gets.


i plan on beating this at lest 1 more time and i'll try to update the stuff i forgot or fix anything i missed. i did not plan on doing a guide at first so i didn't track most things that happened during most of my games but seeing the lack of guides and how the characters work i figured why not. i'll try to clean this up later also.

Hopefully this helps people get a heads up on game play. This is how I play and you may find better ways that work for you.

first off i split my people into fighters or workers.
WORKERS
the first two people that join me become a hunter or guard (unless its Liz she becomes a fighter) and i only put points into that job until its maxed out. i do this so i can max the stat as early as i can. a good weapon for guards is the shotgun with 3 points in it for the spread shot but don't add any more until guard is maxed out also you'll want more then 1 guard after about day 10 even if they only have 1 point. don't worry about making a 2nd guard because some of the late game survivors have guard leveled to the mid point.
you may want to make a dedicated crafted as the better gear and weapons come in handy and grab 1 point in hunting to craft low grade ammo when you need it and maybe 1 point in medical. if you conserve going out and how far you shouldn't need more medical supplies than what you find or get from the shop.

FIGHTERS
i try to make 4 pure fighters, 3 main (counting the main guy) and 1 backup. i try to get melee to the 2nd to last ability so i can hit twice and the gun depends on what points they already have put into them. i do try to have one of each gun (for ammo reasons) but if not i never have more than 1 pistol. when you have extra points grab guard for block or survival for crit. always give the best weapon and gear to your main and let the rest trickle down to the others. this will keep weaker members alive when you're forced to take them on missions also don't forget to swap gear when changing party members.

WEAPONS and how i see them
Melee: unless you're stocking ammo you'll be meleeing so it and strength should be a priority.
shotgun: good at hitting groups and a great weapon for guards. you only needs the 2nd ability but the 3rd can help, though the 4th just seems like a wast of ammo (3 ammo for 125% shot), and the last is ok but it only really helps on bosses.
assault rifle: its good and can hit groups but if you're nor careful you'll burn through your ammo. you'll want the 3rd ability on this for the 5 shots but maxing it if you can spare the points isn't to bad for 7 shots.
Pistol: better damage then melee and good for disabling. its best just to try and max the pistol for the 3 shot ability but stopping at the stun is doable.
Engineering: its not worth taking more than 1 for anyone but the main character because the traps only work on melee attacks (punks have guns) and in a full party have a low chance of hitting. it is fine to take 3 points for the main guy for lone fights but i wouldn't go past that.
Medic: having 3 points in medic can be a life saver and even though the 2nd to last ability is good for curing aliments i'm not sure its worth the points.