(NEWBIE)Just bought MACBOOK

Dear Mac User:
I just bought Apple Macbook. This is my first time bought apple macbook and also my first time use APPLE OSX. Tell you the truth, I love it, it was nice, and the osx its easier to use. I have a lot of questions because its different with windows os.
1) Right now, I'm using battery and charger because im using in my office. Is it okay to leave it together or its better to pull out the battery and using the charger only? I'm considering about the age of the battery
2) What's important software do I need?
3) Where can i get cool icon and wallpaper?
4) Is there any great game but free?
5) Do I need to install anti-virus program? If it needs, any suggestions?
6) Im a messenger user, which program do i need to download to be able to use webcam?

Thank you guys for your really big help. MACRULES

1. I'd leave it be.
2. Depends on what you use it for. An Office and graphics type program would be good starter e.g. iWorks, OpenOffice, iLife, Photoshop Essentials etc
3. Anywhere on the web. Wallpapers for PC will work just as well as on Mac
4. Online games are free such as Shockwave or Java games.
5. No, not really. Try Netbarrier for starters.
6. iChat would work.

for wallpapers and icons you should check out interfacelift.com

i think he meant msn messenger (correct me if I'm wrong)

U can use Adium which is a whole bunch of instant messenger built in to one instant messenger. It's kind of hard to explain. You can talk to people on Aim, ICQ, Yahoo, MSN all at the same time. It's an amazing app, only minus is that it does not support webcam.
www.adiumx.com

aMsn, is a msn clone for the Mac. It has all msn features that msn has including webcam chat (only video i believe not audio and video together) However it is known to be quite buggy at times, and there are basically quite a few problems with it.

Mercury messenger is another msn clone. It has webcam support WITH audio. However i can not tell you about is cos i have not used it. so yeah.

I suggest sticking to adium, any mac user will tell that it's the best messenger application, and if you really wanna do video chatting, i suggest u use skype.

Hope this helped.

thank you guys for the help!! it's really helpful;D