The Bio Q was something they just introduced so no one has any idea how it will be used.
There is a book called ATC Career Prep, AKA The Green Book. It had a CD that included practice ATSAT questions. The ATSAT used to contain math (e.g. Aircraft 1 is going 250, how long will it take to travel 80?), analogy questions, some memory exercises and a really basic simulation. You are not allowed to use paper, pens, calculators, etc... on the test.
However, the ATSAT is getting revised so take the above with caution.
Odds? No one knows.
Since everyone has to go through basics now, tower will be 3 months and en route 4. If you pass, you'll be sent somewhere but don't count on it being your first choice.