I put most of my ideas at the start of this topic in the first few posts.
Oh, and definitely get onto the map thing I made. It's hella useful for navigating and keeping track of stuff - especially if you use the plug-in I made. The map etc work best with Firefox. I couldn't make it look so good on Chrome because of how Chrome scales the images. I'll PM you a link.
One cool idea is to start with a few archers, then sell their useless ammo. It's pretty valuable. Then, gear everyone up with chainmail + short swords from the start, and you should be able to buy more guys. Keep the archers as sword slingers for a few levels until you can afford longbows or crossbows. If you haven't spent many turns on the game so far, then it might be worth a restart after you work out the optimal setup: 2 priests, the rest a mix of archers and warriors. Recommend you don't get a mage for now.
For leveling up, generally focus on just raising your characters main class stat. Raise a little bit of Con at the start. It increases wilderness movement rate, and carrying capacity (so does Str, but I think Con gives a little more). Con also raises HP gain, but the amount it affects is almost useless.
For your priests, the two spells you want to focus on are healing, and portals, but only go for portals once you're about level 5 and hitting dungeons in the wilderness. Gradually build up to 2-3 portals in your party. For the first few levels, priests on 100% healing spells, and stick to dungeon delving in sewers, and make use of the town healer because you won't have much in the way of healing spells.
For skills, just keep raising Beserker Rage for the warriors / archers. I put points into awareness and tactics for the priests (put one on tactics, and the other on awareness, then swap when they max out each skill).