The time there were no battlegrounds, world pvp is all you had. Most of it was ganking people in BRM or maybe fighting over a world boss. Tarren mill... was the only real PVP there was. Then battle grounds were added you HAD to go to the battleground entrance and queue from there. they then added later on NPCs in major cities to queue from (now you just click a button anywhere to queue)
When all I did was PVP I had some very good PVP gear, (got to blood guard I think when I moved to a pve guild) initially I went a healing/enhancement spec then switched to resto when my warrior friend came along for battlegrounds. Gave him WF totem and watched the kills come in as I healed him.
You also used lower ranks of spells to reduce mana cost (for healing in raids or interrupts). That is something I kinda missed a bit but its nothing major.