Hi there.
I've played on al'akir for the better part of 5 years
And.. I've played a hunter for those past 5 years
And, I also play a warrior fulltime now in Cataclysm.
Anyway, yes, a Warrior does acquire you to pay attention all the time. Especially at the current cap (85 as KeyJ told you). We have a massive arsenal of tools available to us. There's like 15-20 cooldowns you can use besides your normal skills and you have to keep track of what's on cooldown whether you're pvping or pveing.
What spec are you? I suggest Fury for lvling. Arms and Fury are quite even and scale with your Strength quite evenly throughout the lvling process. Basically Arms is currently best for PvP, Fury for PvE, and Protection for either, but mostly PvE.
Raiding is indeed like KeyJ said not that important for you until level 85. There are raids available however at 60, 70 and 80 as these were the end-game content level caps in the beginning of the game, and the last 2 expansions. I would suggest lvling to 85 first because you'd outlevel the gear you might get during these raids since every expansion there's a massive Stat-jump on the items that scale with your character to the new level cap so anything you get is rendered useless a few levels into the expansion at the very most.
For tanking tips, I suggest that you do some dungeons. It's rather easy at the lower levels, especially if you pick up the top-right talent in the Protection tree called Blood and Thunder.
If you pick that up, you will want to Charge in, Rend, Thunder Clap (Thunder clap then applies Rend to all targets within range due to the talent), and then a Demoralizing Shout. Just use your main tanking abilities to gain and keep aggro on the mobs after that (Revenge on Proc, Shield Slam (later on), and Heroic Strike for ragedump purposes which give you extra threat). Use Devastate on bosses and spam it even if you reached 3 stacks of Sunder Armor on it, and use Shield Slam and Revenge whenever available. Also keep Thunder Clap and Demo shout up on bosses as this GREATLY reduces the damage they do and it's prio #1. It doesn't really matter what 1hander you use anymore in terms of it's attack speed, especially at lower levels.
You'll get some important cooldowns on the way up, like Shield Block, Shield Wall, Last Stand etc but by the time you get most of these you'll know how to play.
Have a look at some of the big leveling guilds on Al'akir, there are plenty that would like to have you especially now with the Perks which help you in many ways. Extra XP, extra mount speed, etc.
Addons that are a must for you as a tank, are Omen (It's a threat meter, shows in you dynamic bars how high your threat is, and you can see if someone is about to get aggro or something). DBM (Deadly Boss Mods) which gives you timers and warnings on a boss's special abilities.
If you have any questions fire away
