My early game strategy:
Talk to your troops straight away and create a regiment, then transfer all your troops into it and put it on follow. Then run around by yourself at great speed and go from city to city collecting companions. Compete in tournaments and do quests for guild masters for money + xp that levels your companions also try to build up a decent force from hiring merc's and peasents, you can transfer extra troops to your regiment, so you can move faster.
Use your companions to develop party skills like pathfinding, tactics, healing skills, looting etc. Alot of people in these forums seem to suggest dumping all points in strength for plate and war bows, I find this difficult to understand? Its best to have 3-4 combat companions and 3-4 skill companions, with redundancy in all crucial skills (wound treatment, pathfinding). I specialise in all the charisma skills + fighting for my hero (trade,leadership etc) so I dont have to raise another companions charisma at all.
After a week or two you want to think about taking a castle. Look for castle's that have been taken by a faction, because they will then leave a minimal garrison there. Also like Jasonx says, look for faction armies with alot of prisoners and attack them, this is one of the best ways of getting troops and you only lose a bit of rep with the faction for attacking an army, so its easy to pay them for peace.
Good idea to look at Magelord's tweaks too, personally I have it so you can repeatedly ask guild masters for different quests + increased chance of ransom for captured lords
This is as far as I've got in my game, Im currently trying to build up enough of a force to take another castle (one thats more heavily garrisoned) but my castle is constantly being attacked
Actually I got a few quick q's for Jasonx (raptor jesus guy)
Can you explain again about in sieges- parking force at ramp, killing all their archers on wall then leaving and auto-resolve (I saw something about this in another thread). Does this only work with alot of archers on your side? haven't tried this yet sounds like a good plan.
Also, who/where is the guy you can trade all prisoners to for 250denars? is it the ramun slave trader guy? sounds like it could be useful later on when the prisoners start rolling in
cheers