Well, which online school is a choice to make. Just google u'll find plenty. Their location dont matter, as long as they're online and have humans teach (instead of bots or recorded videos)

Dvds are really inexpensive and the makers most of the times are industry pros.However, with dvds, u cannot really ask queries, just watch em all over again.SO, it would be great if one has some basic level of working knowledge of the software, then dvds are super.(This is just my humble opinion)

Initially when ure starting out you'd rather learn from a human and u're sure that u're following along.
The trick is that even online programs shouldnt be expensive. They should cost you under $1000, so you'd get a good foundation and then once u're comfortable, u'd wanna dive in deeper.
I've known people who've spent lot of money and time going to schools, and still having average knowledge, or sometimes even lower than average.
I dont wanna be pro some school but yeah, research online 3d schools, and do a short 1 or 2 month program. You wanna learn faster and spend lesser (u're gonna spend a lot making, editing, making dvd copies, mailing etc for your demoreel later).

Oh yea, make sure your course, has some kinda goal, final scene that u're gonna create. Not just the tools and commands.
Make sure your school/instructor has that set for you.
That way, although a basic one, but you do have a demoreel right away, boosting your confidence, and learning the way real life industry works.

Hope this helps.