Connect how? File sharing, printers, one's a web server and the other's a client? If they're both plugged in to the hub and on the same subnet, they should be able to ping each other already: more than that will depend on what you want to do.
For file sharing, you've probably already got a samba client on the suse box, and can connect to file shares on XP in the usual way - usually by opening "Network Places" or something like that in your file manager.
I won't waffle any further - more information on what exactly you're trying to connect please!