ms B get a Linksys. the wrt54G2 is probably the best bet at 45$ or so. The "2" suffix is the new look and comes with the MAC "instructions". Earlier versions did not and had to be set up the old fashioned way first. Linksys are now part of Cisco which is a GOOD thing.
If at some point you want to print wirelessly you can get several wifi printers that really work. I have a HP Photosmart that does photo qual, regular qual , copying, faxing and works usb/ethernet/wifi. I am using it wifi currently. The printer has MAC drivers. As for the dell, persuade your work IT people to load any drivers you need AND you may need to persuade them to allow the machine to use wifi.