For you non-WoW players out there, PvP stands for player vs. player, a part of the game where, instead of fighting virtual monsters, players battle each other. There are PvP servers where this kind of fighting happens constantly in addition to the virtual monsters fighting one must do. But most PvP action takes place in special battlegrounds where a group of Horde players battle a group of Alliance players in trying to reach a certain objective. There's a capture-the-flag-like place, a place where one holds bases (actually several like this), and a place where one is trying to reach and capture a certain area. Naturally, as one tries to achieve these objectives, players from the other team will try to prevent this from happening, usually by killing people. Killing other players and achieving the objective rewards honors points, which can be used to purchase some cool items.
Back when I first started playing, I tried PvP and generally hated it. My fingers did not move fast enough to counter attacks or attack much myself. But there were some good rewards that came from honors points, namely swift mounts. So I suffered through enough battlegrounds to get my mount and then never really went back. But then, they made it possible to gain experience through PvP. So, I decided to give it a try again with my alt, an undead priest. I was struggling with leveling it because I found questing to be getting a bit tiring. As a priest, it's also difficult to level simple by killing off a bunch of creatures. To vary my activities, I thought I'd try leveling via PvP.
When I first did this in my 20s, it hardly seemed worth it. I was in Warsong Gulch (a capture-the-flag-type game) and I was rewarded experience only when our team captured the flag and then more if we won. If you're losing, you don't get much experience at all, a token amount I believe at the end. So, I held off on that for a while until I got access to Arathi Basin, a battleground I've always liked, even when I didn't like PvP more generally. I happened to venture back in this past weekend on its holiday weekend, when both experience and honors points are increased. I was level 38 when I started. I'm now level 43. Some hard-core players would probably have leveled to 50 by now, but this is only doing a few bg's a day, throwing in a couple of quests while waiting to be let into battle. You can often complete an AB battle in 10 or 15 minutes (if you're really kicking butt) and at most 30 minutes. This makes it easy to hop in over lunch, do a quick bg and then go back to work. You can also earn experience by doing the daily bg, for which I've been receiving around 7k xp. In AB, I've been getting 7-10k xp for each battle, a little less when we're really sucking.
The other reason I hopped into PvP again besides wanting a more fun way to gain experience was that I wanted to try out healing in a group. I especially wanted to test out the effectiveness of two healing addons I was trying: healbot and grid+clique. It's hard to find a group for a low-level dungeon these days, so hopping into a bg was an easy way to be in a group quickly. And I was able to test out my addons and settled on grid+clique for now. I've found that I enjoy healing in a bg better than attacking and that healing is much appreciated. Like in dungeons, where keeping the tank alive can mean the difference between defeating the boss or not, in bg's, keeping a powerful player alive can really make a difference between winning and losing. I am often thanked for healing. And no one ever makes fun of me for dying since as a cloth-wearer, that's a common event.
One reason that I didn't like PvP before (besides sucking at it) was that the chat in PvP often degenerated into insults about how bad the rest of us are at the game. I still see that, but I'm able to tune it out most of the time, and I have also been in plenty of bg's where that doesn't happen, possibly because I'm often doing them at lunch, when there aren't any kids online. When it's a bunch of other grownups getting in a quick WoW session over lunch, there's less likely to be any moaning and groaning.
Once I hit 80 with this alt, I'm not sure I'll PvP much. Most of the rewards for PvP are PvP gear and if you're interested in doing dungeons and raids, that gear isn't going to be so helpful. Plus, I like the quests in Outland (lvl 58 and up) and Northrend (lvl 68 and up) better than the old world quests so I might be hitting bg's less often as I get up to those levels, though I hear Alterac Valley offers some good xp. Only 8 more levels to go before I get there.