Hi
Welcome to the forum.
The following thread should answer some of your questions about dropshipping:
http://traderonlineforum.com/index.php?showtopic=10
As for what to sell, as you have already seen from other posts, there is little profit in highly competitive products such as mobiles, computer equipment, console games etc. Find a smaller, less competitive niche - that is where the money is.
Of course, that is the hard bit but trading in products that you have an interest in is always a good start.
Cheers
Richard
TheTrader