If you like BGs, then keep getting honor points and marks. When you have enough, you can buy the S3-matching non-set items:
Vindicator's Ornamented boots,
Vindicator's Ornamented waist, and possibly
Vindicator's Ornamented bracers.
You can also easily obtain the
Vindicator's Pendant of Salvation, Vindicator's Band of Salvation, and
Veteran's Band of Salvation. These can all be purchased for honor points and the appropriate marks from the appropriate vendor in Champion's Hall or the Hall of Legends.
You might be able to find better +heal on some PVE items, but each of these pieces will give you a huge stamina boost, some decent crit rating, and your first bits of resilience. You can mix in the blue PVP rep gear from this last patch if any parts of your remaining dungeon blues/quest rewards are particularly lacking.
You should also want to make getting the PVP trinket a priority, but that advice is not unique to holy paladins by any means. For alliance, you want the
Insignia of the Alliance and then the upgrade,
Medallion of the Alliance, at your earliest convenience.
You'll still get owned, repeatedly. These'll get you started though until the arena points start trickling in.
[EDIT] Fixed ugly comma usage.
Edited, May 28th 2008 11:50am by HoyadinFTW