If this is your first time playing DAoC, or it's been way too long to remember any details, I posted a huge amount of info in my old thread from 2014 which is linked to by the first post. However, if you don't want to go through all 29 pages worth, you can find most of the relevant information in the links under my sig.
I wrote out all the class descriptions myself, while trying to compare them to their "EQ versions," use that Character Builder to see how many abilities you can obtain by a certain level, though I'd personally suggest you plan it out for no more than 10-15 levels ahead. Most players think its best to just plan your spec for level 50 and just randomly invest the spec points, but unlike EQ, you can actually re-spec later down the line if you end up not liking your current spec path.
You'll be able to try things out in the BETA before making a final choice when the server goes 'live.' Check out this site here, for a few extra details regarding the BETA period:
Uthgard: The Free Dark Age of Camelot Shard Open Beta Due in May.
P.S. Check out the 'Current Guild Roster' link in the sig, at last count, we had at least 55 people wanting to band together under 1 guild, 34 from the P99 forum alone.