Set up white, black or a combination of both colors of foam board (found in office supply or craft stores). Use one for base and one for background.
Set up your camera on a tripod close to the setup. 6" to 8" above table level should be good for most small items.
I have also used two more foam boards, scored on the back so they are self standing, to create sides to my "photo booth". This will provide neutral reflection for lights or shiny items.
Set your item at a slight angle in the center of base foam board. Don't put it too close to the background foam board.
Make sure your item is as clean as you can get it and begin taking your shots. Natural lighting is best. Window or ambient light. Never use an on camera flash for these type of pictures!
Frame your item in center and zoomed in fairly close. I am at about 70mm using a dslr camera. Take a picture with your item as it would appear on a shelf at the store. (In its packaging if possible)
Begin unpacking your item and take a picture at each stage.
Then take some shots of the actual usable product. Try to get one of each side of item.
Now create your eBay (or whatever) ad and upload your nice clear uncluttered pics to see great selling results. Much better than blurry, cell phone pics with yesterday's laundry in the background! :)