You never need to remove the battery. You can leave it plugged in for years. I do, and my battery is fine.
The configuration you received is a "baseline" meaning that IBM tested all of the features with that set of software and released it as meeting spec.
Before you start updating drivers, BIOS, etc, You should familiarize yourself with all the wonderful little features IBM packed into the Thinkpad. Explore what the Access IBM button does, and the Access IBM menu (Start->Programs->Access IBM) has to offer, learn about setting up your wireless (if you have it), learn about Fn+spacebar, Fn+F3, Fn+F4, Fn+PgUp, etc all do. Explore the UltraNav features, fingerprint reader (if you got one) -- there's a lot to explore.
After you feel like you're ready to graduate from Thinkpad 101, then I suggest you download the new ThinkVantage Software Installer that will update your drivers and software automatically. Follow this link to get that software:
http://www-3.ibm.com/pc/support/site.ws ... OFT-UPDATE This program replaces the old Updater program.
Don't worry about your BIOS version. Unless there's a specific problem you know has been fixed, it's rare that a BIOS update makes any noticable changes at the user level. With the T42, most all of the problems that can be fixed in BIOS have been fixed long ago. I know that T43 users would love to see BIOS fix for their widely-reported fan problems, but T42 users can relax. Know that the new Software Installer also checks the BIOS for updates. If and when you do get to the point where you re-flash you BIOS, follow the instructions exactly. Undock your thinkpad, have a fully charged battery and have it plugged it wall power. Flashing BIOS is playing with sharp knives and if you screw up, your Thinkpad will wind up a paperweight attached to a really nice keyboard.
Enjoy your thinkpad!
Apathy is on the rise, but nobody seems to care.