The gouge online was spot on for me. Back then we had 3 tests (not sure if we still do) One was a coordination, memory/recall etc. Basically video games that test hand eye coordination, and mental ability. Some said lumosity games helped. I found it not hard at all. However I play tons of games already in spare time. So who knows.
The other was a personality test, and the other was aerodynamics. Many math questions revolved around things we simply dont do any more. For example, the long hand way of figuring out a navigation "direct to" type scenarios. But its on there, so study it. Things like the 3-1 rule are a must know, and converting C to F or F to C sometimes comes into play. Like I said, the gouges online were dead on accurate for me.
I read some jeppessen turbine engine guide of some sort for the topics like compressor stall, surging etc. There is also the Naval Aviator book alot of guys like to. Just cant recall the full title of the book. Aerodynamics for the Naval Aviator? I think.
But more than anything, try and be a good fit. Be yourself, be nice, be social, be professional. Compass doesn't just hire anyone with good scores.
Good luck!