hi, we have been lanzarote with our two young ones. there is alot of family holets/apartments to chose from that have kids clubs and enterainment on at night.
my advice go and get a load of books from the travel agents, pick where you would like to go. i first look at the flights to see the flight times, (i only do day flights). then find hotels with kids clubs. then check prices on the web and last before i book is look at reviews of the hotel to get an idea. i also see if my local travel agent will match the web price.

thomson, firstchoice, jmc, airtours all do kids clubs.

hope this helps

We're going to Fuerteventura next Easter - the Club Caleta Dorada, which is a First Choice property and has loads to do for kids, they have a choice of AI or SC, it wasn't 'cheap' but if you want good family facilities on site then you'll probably pay that bit more wherever you go. It would be a good idea to check out the 'direct' tour operators: Eclipse are part of First Choice, Portland are part of Thomson/TUI, Direct Holidays are part of Airtours
As Easter 2007 is quite early (first weekend in April) I'd recommend the Canaries or possibly Cyprus or Egypt for the weather. Mainland Spain/Balearics/Greece may still be cloudy and damp so early in the season. However if you go at Whitsun (end of May/beginning of June) you should be able to expect great weather anywhere in the Med