Wizardry 6 has multiple endings, and, if you import your party into Wizardry 7, the choices you made will alter how the sequel starts.
The endings themselves are nothing complex, and neither is the act of looking up information about them. How these endings influence the sequel, though, is another matter entirely.
In order to save new players the trouble of looking that stuff up and potentially finding out things they rather wouldn't, I have compiled the necessary information in this short but hopefully helpful guide.

Before I get to the endings themselves, it's important to describe what is actually a major branch in this game. What you do here determines how some of the other endings work.
Having spoken to the Queen, you receive a silver cross. You can either equip it or throw it away.

Equipping it will take you to the branch where you fight "Dracula" and Rebecca near the end of the game.
Throwing it away will lead you to the branch where the fight does not happen.
The fate of Rebecca will influence whether you have to fight another NPC right at the very end of the game or not. Equipping the cross blocks you out of getting one of the endings (but you probably don't want it either), but being friendly with the vampires blocks you out of the fight and the rare loot that you would get if you had won.

Having looted/received the key from Rebecca, open the door and simply go forward. You will be offered to take the Pen. Type "yes".

In Wizardry 7, this will give you the safe start in the Wild Orchids field. You'll start very close to the city and a dungeon. The fights in this area will be fairly easy. Your reputation with the factions will be intact.

Having reached the room with the Pen, do not take it. Instead, go behind and pass through the torch. Use the key again and you will enter a room with a large dragon. The dragon will offer you to go with him. Type "yes".

In Wizardry 7, this will be referred to as "traveling with the Umpani". It is a fairly difficult start. The starting area here is full of dangerous monsters, and you will have a bad reputation with the T'Rang faction.
Alternatively: if you went along with the silver cross 'quest' and did fight the two undead, you will have to fight the dragon as well. You won't be able to get this ending (leaving only 1 and 3), but you will get good loot to export into the next game.

If the dragon was peaceful, tell him "no" and go on your way.
If you fought and killed him, you've sort of already turned him down.
You will eventually encounter a device from the previous ending and use it, except you'll be traveling alone this time.

In Wizardry 7, this ending is recognized as "traveling with T'Rang". It's going to be a difficult start. The monsters surrounding the starting area won't be particularly hard, but you'll have a bad reputation with most factions.