Ok this is an easy one.. You need to get a USB cable and software. The download link below, is for the driver, you install this Driver, as administrator, right click, install .exe and select run as Administrator http://www.olympus.co.jp/en/support/imsg/digicamera/download/software/
Now after you install the software you plug in the camera to the PC, via the USB port, (any) and then turn the camera on, it should be detected and then you run the software and "Get" you pictures. Also to help i recommend you get a Picture resizer, and use it to make the pictures the right size to send.. Link below, http://www.microsoft.com/windowsxp/Downloads/powertoys/Xppowertoys.mspx get it and down load and install, like before, then when you wish to resize a picture, you right click, and select resize.. follow instruction, then you can "Attach" the Picture to an Email.
If you don't have the cable etc. get one from say eBay...link below to give you the idea.
http://shop.ebay.com/i.html?_nkw=Olympus+Camedia+D-550++usb+cable+&_sacat=0&_trksid=p3286.m270.l1313&_odkw=Olympus+Camedia+D-550++usb+cable+a+and+disc&_osacat=0