Well generally to use the Linux box as a proxy server, you will need to use IPMasq.
Here is a pretty good site on setting up IPmasq.
As far as getting the printers to work through samba, I haven't had much luck with my HP printer working.
As far as the browser, you only have a few options, one is Mozilla. The others are Opera and the new Konqueror. Linux mag rated Konquerer the number one browser. It is part of the KDE family.
Hope this helps.