49s officially play starting 10pm EST/7pm PST on Mondays, Thursdays, and Saturdays. That said, games actually tend to get going about 10:30/7:30 or so. Like with other midbrackets, gamenights have been hit or miss, but still going. I've seen a growth of interest lately from a few new players, which should help stabilize game nights. Definitely check out the 49 thread in the official WoW forums for more info.
If you haven't updated your gear since the Shattering, you'll definitely want to do so before getting on the field. With the burst as high as it is, 49s typically recommend a minimum of 4K health on any toon, to get started. I've seen 3.3K crits, as a reference. The bracket's also helpful with gearing up and so forth, so depending on what server your 49 resides, you can get help with your updates.
If you like, post or PM your toon armory, and I can help point you in the right direction for the updates that will make the biggest impact for you.