You have to be level 20 to get to 225 and 35 to reach 300. However you have to go to Annora in Uldaman to get the ability to train to 300. As you will have to go through level 35 -41 Elite mobs to reach her, It might be a while before you can get to 300 unless you have high level friends to help you. I got to her at 46 solo (Warlock) and it was tough. Its a good idea to take a lot of mats with you to up your skill and get all of her recipies at once. Note she only gives you the capability to reach 300, you are still going to have to do a lot of work and spend a lot of money to reach that goal.
NB Just reread my post and realized I didn't make it clear that its only enchanting you need to go to Uldaman to get the ability to reach 300 =)
Edited, Sat Oct 8 12:48:10 2005 by Deadshot