Max,
Welcome to our addiction![>:]
Like Rick was saying the stock battery is only good for a few minutes, then you have to charge them for 1 1/2 hours for another few minutes of flying. When you're getting the hang of hovering you don't want to wait because your battery is low. I'd recommend researching LiPo battery packs, a good LiPo charger and a good LiPo battery balancer. Just keep in mind, if you go cheap, you'll wind up wanting more. The recommended BP910 is a good battery but will only get you 10 minutes of flight. I am looking at buying a couple of 1320 mAh packs. I've been told that I can get 15 to 17 minutes of flying time. The bottom line is that you are going to want more than one battery pack. The LiPo packs still take an hour or more to charge up. I've looked at a couple of chargers that can charge up to 4 LiPo packs at a time. Most chargers are 12 v DC. You can find a few that run off both AC/DC or you can go to Radio Shack, buy a 110 v AC to 12.6 v DC plug and a few connectors, do a little cutting and soldering and now you can go AC/DC.
There are tons of mods out there, just research the threads on this and some of the other forums. When it comes to parts, Tower Hobbies has everything you'll need, but if you do a little research you can find other hobby shops have the same parts for a few bucks less. Tower Hobbies has some nice discounts though.
I started a thread on this forum a few months ago looking to put together a crash repair kit of the more common parts that will break in the event of a crash. Believe me when I say this, you're gonna crash.
http://www.rcuniverse.com/forum/m_6177027/tm.htm Read up on this thread, it's a good source of parts info.
One more thing. You can learn to hover and fly on a simulator pretty quickly and save money on parts you break or you can learn without a simulator and replace the parts as they break. It took me a few days to hover with the simulator and a week to do it for real. It probably would have taken me several weeks to learn without the sim.
I know this is a lot of info to digest. Bottom line is this hobby is tons of fun and very addictive. I go into work an hour early and stay an hour late just to get in some stick time. The main reason for not flying is waiting for parts!
Ted