If you want something to do on the internet:
-StumbleUpon. Select the things that you're interested in and it comes up with a huge selection of websites to browse. http://www.stumbleupon.com/home/
- Neopets. There are loads of games to play and lots of stuff to do. People think that it's a kids site, but there are loads of older people on there to talk to. http://www.neopets.com/refer.phtml?username=strictly_guinea_pigs
-Online shopping! This is the most rewarding thing to do online if you've got some money, cos getting new clothes and stuff through the post is awesome. Use Google to find online shops that interest you, and don't forget Ebay if you want some bargains. www.ebay.com
-Youtube. There are loads of good videos on there, you can search by the most popular ones to find the sort of thing that you're interested in. It's also a good place to find new music and stuff.
Other things:
-Learn to do something. You'll find it really rewarding. Is there something you've always wanted to know how to do? Play an instrument, juggle, do the splits, etc.
-Go on a picnic or out for a meal. Get some of your friends together to do it.
-Go to the cinema, or watch a film at home.
-Read a book.
-Play video games.
-Throw a party - maybe a BBQ if the weather is nice!
Hope I helped!