Hiya! Ur gonna have a fantastic summer where ever you decide to stay in Ibiza!
San Antonio is the most popular resort it's in 2 sections San Antonio Bay & San An Town. San Antonio town is where you find the sunset bars where you'll watch one of the world's best sunsets, the West end which is a group of streets packed full of bars and small clubs which play all kinds of music from cheese to dance. When walking though the streets the PR's try to drag you into all the bars so be ready. Also in San Antonio you'll find the clubs Eden ( Judge Jules, Lisa Lashes, Dave Pearce, Paul Taylor etc play here) & Es Paradis ( DJ Sammy, Boogie Pimps, famous 4 water party where dance floor turns into a swimming pool! ) San Antonio beach is pretty standard but has some nice chillout bars along it which leads you to San Antonio Bay. Popular with families the hotels in San Antonio Bay generally offer you a better nights sleep ( if thats what you want) and are still only a short walk to the action in San An Town.
Playa den Bossa is on the other side of the Island, a lot more Ibiza's more experienced visitors stay here cause they have done the San Antonio thing and want a more laid back party atmosphere. It has Bora Bora beach, Space and the waterpark. If you like chilling out on the beach or love to carry on partying after the sun has came up Bossa is the place to do it!
10 mins from Bossa is the capital Ibiza Town, well worth the visit! If you climb up to the top of the old town you get fatastic views loads of history and culture. Good for shopping and clubbing, Pacha ( Erick Morillio, David Guetta, Trevor Nelson) and El Divino ( Hed Kandi, Miss Monneypenny's). Very trendy bars and funky atmosphere. Lots of tour operators don't have hotels in the capital itself tho.
Other resorts on the island are Es Cana, Cala Llonga, Santa Eulalia which are all a lot quieter. There is so much to do the best advice is to have a rough idea of some things you want to do or try before you arrive but dont plan exactly. You can get anywhere in about 30 mins in Ibiza so you'll never have far to travel.
Hope ive helped. Brace yourself for a wicked summer. . .