You might be better off staying with FTP...

First, are you sure they're running AppleTalk? Apple themselves are ditching AppleTalk in favor of TCP/IP. OS 9 and OS X will both work with both, but TCP/IP is the preferred protocol.

If you're trying to connect to file shares on computers running Mac OS X and TCP/IP, you can access shares on those computers if they go into File Sharing in their System Preferences and enable "Windows File Sharing", which would allow your computer to access shares on their machines via SMB.

If you're trying to connect to file shares on computers running Mac OS 9, AppleShare IP Server software, and TCP/IP, they can configure their servers to allow access from Windows machines via SMB. Open the Mac OS Server Admin (in the AppleShare IP folder), then click on the down arrow next to the file sharing icon and select "Configure File Server". On the Windows tab, there's a box labeled "Enable Windows File Sharing (SMB)". If that's enabled, you can access it from your Windows XP box, just as if it was any other Windows-based computer.

If you're trying to connect to a pre-OS X Mac that isn't a server... Sorry, you're out of luck unless you use a third-party program like Thursby Software's DAVE.

As for print sharing, you might be better off printing directly to the printer via TCP/IP if it's a network printer. I'm not aware of a method other than something like DAVE to allow a Windows computer to print via a Mac network.

As for accessing the web server you mention... If it's a web server, it has to be running TCP/IP. If you've got its address, you should be able to access the web site from a Mac, PC, or any other platform with a web browser. If it's a proxy server you're talking about instead of a web server, you can probably still access it via PC, but the method of doing so can vary depending on whether or not it requires authentication of some sort.

The bottom line is that for file & print sharing, there's nothing you can do to just your computer to make it work (unless you can find some piece of software to make it work that I've never come across). Some configuration will need to be done on the Macs you're trying to access, too.