--> https://bardstale.brotherhood.de/talefiles/1/docs/BT1-Walkthrough.pdf
Read the first three paragraphs, past that is the actual walkthrough if you desire

You generally want 4 melee characters and 2 spellcasters, optional in remaster to have a 7th party member
In the remaster Monks/Paladins/Warriors gain extra attacks at levels 5, 9, 13, etc.
--> https://bardstaleonline.com/bt1/library/characters

--> https://bardstaleonline.com/bt1/library/bestiary

--> https://bardstaleonline.com/bt1/library/items
Note that weapons in the remaster you can hover mouse for damage and some items have information on hover too

Note that spells you know you can hover mouse over the spell name for information about the spell
--> https://bardstaleonline.com/bt1/library/spells

Well ok then here! you can hover ingame too
First a helpful hint: You can have one travelling bard song going outside of combat which will give you the combat effect once combat starts, you can then ALSO during combat use your bard songs and they do not overwrite the travelling song they add effects which last until the end of combat only, then the travelling song continues
--> https://bardstaleonline.com/bt1/library/songs

holy moly check out all these maps they are awesome
the grid numbers on these maps are for use with the APAR (edit: APport ARcane) spell if you choose to teleport around you will need these grid references

Skara Brae --> https://bardstaleonline.com/bt1/maps/skara-brae

Wine Cellar --> https://bardstaleonline.com/bt1/maps/cellar_1
(hint: go to the SE inn in skara brae and order a Wine)
Sewers Level 1 --> https://bardstaleonline.com/bt1/maps/sewers_1
Sewers Level 2 --> https://bardstaleonline.com/bt1/maps/sewers_2
Sewers Level 3 --> https://bardstaleonline.com/bt1/maps/sewers_3

Catacombs Level 1 --> https://bardstaleonline.com/bt1/maps/catacombs_1
(hint: go to temple of the mad god and speak the name of the mad god tarjan)
Catacombs Level 2 --> https://bardstaleonline.com/bt1/maps/catacombs_2
Catacombs Level 3 --> https://bardstaleonline.com/bt1/maps/catacombs_3

Harkyn's Castle Level 1 --> https://bardstaleonline.com/bt1/maps/harkyn_1
(non-spoiler spoiler in case you don't want the hint direct access from Skara Brae, northwest corner)
Harkyn's Castle Level 2 --> https://bardstaleonline.com/bt1/maps/harkyn_2
Harkyn's Castle Level 3 --> https://bardstaleonline.com/bt1/maps/harkyn_3

Kylearan's Amber Tower --> https://bardstaleonline.com/bt1/maps/kylearan_1
(hint: accessed via Harkyn's Castle Level 3)

Mangar's Tower Level 1 --> https://bardstaleonline.com/bt1/maps/mangar_1
(hint: accessed via sewers level 3)
Mangar's Tower Level 2 --> https://bardstaleonline.com/bt1/maps/mangar_2
Mangar's Tower Level 3 --> https://bardstaleonline.com/bt1/maps/mangar_3
Mangar's Tower Level 4 --> https://bardstaleonline.com/bt1/maps/mangar_4
Mangar's Tower Level 5 --> https://bardstaleonline.com/bt1/maps/mangar_5

I hope this helps you like it helped me!