Don't bother with the pyramids
If you've got kids in tow then I'm afraid you're in tourist hell.. so, make the most of it
Siam Park, Loro Park, Teide (hopefully the wind stays down and you can get up the cable car), Whale & Dolphin watching (dolphins not guaranteed, pilot whales normally are), if you can get a car, take a drive to masca (unless mountain roads with no barriers give you the shits). The north of the island is where the "cities" are (they are the size of Milton Keynes, can't really call them cities) the south is where the Sun and beaches are. Steer clear of Veronicas unless you want to get ripped off paying 15 euros for watered down beer.
Dorada is the beer they make on the island, it can be potent if you're not used to Spanish alcohol!
The buggy adventures are great fun, but again really expensive, you might come away disappointed as it doesn't feel like much time spent buggying!
Otherwise, eat, drink & be merry! You're in a good part of town for food and drink, if it's still open I recommend Otello II for garlic chicken, it's about 6 euros! If you want more fancy pants restaurants, take a look at Molino Blanco (White windmill) or Coeur de Filet - booking will be needed in both, and make sure you've got double what you normally pay for a meal, but the food is awesome in both.
Los Christianos is best for shopping, if that's your thing, you'll get some bargains down there, but beware, you'll also get some knock off stuff at full price, so check everything carefully.
Can't think of anything else for now, if anything strikes me I'll post again! Enjoy tho, the weather will be good, the beer cheap and the water warm!
I've plumped for Fuertuventura, or however it's spelt... any tips for going there with a bairn of 3 years?
Sunscream & a hat, a big hat. And swimming nappies if shes not potty trained.