Linux on laptops can be a problem sometimes, as I know that's what you have. Especially new laptops. The best solution is usually googling for your laptop model followed by 'linux'. Usually someone will have tried this beforehand and maybe even posted what worked/didn't work online somewhere.
Many browsers are available in Linux.. including Opera, Netscape, Mozilla, and especially Firefox (the most popular). Gaim is also the most popular IM client for Linux. It's a multi-client IM, so it's pretty much like Trillian. In fact, the Gaim team and Trillian share their work occasionally (I remember Trillian figure out how to get around Yahoo!'s block and let Gaim in on the secret) Gaim is also the base for many other IM clients (including Adium for OS X). Webcams can be a bit tricky to get working. It really depends on the camera itself.. because most companies don't release Linux drivers for things like that and the Linux community depends on people to reverse-engineer the technology to release drivers. Many webcams use the same chipset so one driver will work for dozens of different cams.
There are some great dev IDE's for all different sorts of stuff. It's common to just use text editors for development of all sorts but there are also bigger things like Bluefish and KDevelop that are both popular. There are thousands of Linux programs at
www.freshmeat.net and
www.sourceforge.net .
Knoppix is a great distro to try out but not the best to totally base Linux on. Mandrake, Fedora, SuSE and Debian are all good distros (my favorites being Debian and SuSE).
A few good resources are:
www.distrowatch.com - latest updates on all the distros and a few reviews.
www.justlinux.com - great linux forum I used to populate (biggest one I know of)
www.linuxquestions.org - Another linux forum