My suggestion / opinion ..

Go for automatic transmission : because Manual exam takers are more, in Automatic they send you in a van.

Types of test are four
1. Traffic signs.
2. L Parking (Reversing from slop)
3. Packet Parking
4. Road test (*many people fail in this)

Pay 100 riyals ASAP to instructor (pay only if you are sure this is the instructor you want)

If you are American their is no hard process for you, but I didn't see the same rule for UK citizens.