You have to do an approved course so there is a record of the amount of time you spend studying. Believe me, this is like nothing you've ever had to study for in the US. It's not so much the content (if you have an engineering background) as it is the sheer quantity of information you're supposed to cover. I'm having to remember stuff I did in high school physics!

Have a look around, there are cheaper courses but if you're after quality of notes, distance learning feedback and overall experience with JAR exams, OAT is the way to go.

On the other hand, when it comes to the flying you might want to shop around. OAT is bloody extortionate when it comes to what they charge per hour.

Oh and make sure you get a JAA Class 1 medical before you start. The initial medical over in the EU is much more involved than it is here and you might want to make sure you can pass it before spending the $$ on a JAA theory course.