Enchanter/Tailor

My previous priests have had Engineering/Mining and Leatherworking/Skinning. Both are great professions, with their own various benefits. However, since I'm starting my first character on a totally new realm, I decided to go with the classic choice of Enchanter/Tailor.

When finding gear gets difficult, I can always craft my own pieces. I was also able to make a 6 slot Linen Bag to replace the 4 slot Magister's pouch I received on a quest. Certainly, I could have easily spent the money to purchase new bags and gear, but if your priest is your first character with no other caches of gold to draw from, this profession may be the one for you.

As an enchanter, it is tempting to disenchant every green you come across. However, I found it is more feasible to farm items needed to create greens in tailoring and disenchant those. The greens you come across can easily be sold at the Auction House!

Also, another great source of revenue is selling the wands you make with enchanting. These are better than most wands you find at same level (you get far better DPS), and sell very well at the AH.

As an added bonus for priests when they reach Master profession level, you can also use Tailoring to create threads to add spell enhancements to certain items. With enchanting, there are Bind on Pickup ring enchantments, one of which are meant for healers and spell dps! Best of all, tailoring allows you to create bags for general use, Warlock's soul bag, and certain profession uses (like herbalism and enchanting).

Whichever profession you choose, make it your own. And start early! Tailoring, like skinning, allows you to level up and gather materials for your profession at the same time, so starting early ensures that you don't have to waste time fighting mobs that don't give you experience.