It's great that you differentiate between interval training and HIIT which are two different animals. If you are not conditioned, I would suggest holding off on the HIIT training until you build a decent fitness base. True HIIT training is extremely demanding. Progression is key.
You can get in good shape using intervals with bodyweight and with bands, dumbbells, etc. If you are looking for specific routines or something you can follow along with at home, Bodyrock.tv is free and can be modified depending on your fitness level. The website is a little over the top, but if you can get past that stuff, the workouts are always changing and they have a large archive to choose from. They do use some equipment you may not have but you can always substitute with a different exercise. The workouts are generally 12 - 20 minutes and I think there may be a sparkteam for it.
I know I've found others on exercise.about.com, bodybuilding.com, etc. There are tons of them out there.