If you want to continue with the bow, you should get powerdraw to at least 4, which will allow you to use war bows. Horse archery wouldn't be a bad idea either.
For polearm, a good riding skill is a must. To effectively do couched damage with a lance or other polearm, you need a horse that is fast, which requires a riding skill in the neighborhood of 3.
Leadership is a must if you want to raise a large army.
There are also party skills to consider (like tracking, first aid, etc) but I'd pick up Marnid and Borcha before I invest too many in those.
If there are things I've mentioned that you are unaware of (like how to get Marnid and Borcha to join you), do a search on the forums and be sure to check out the sticky threads (FAQ in particular).
Oh, and welcome to the forums (yay me, I beat Narcissus!)