You might find useful help here in the Single Subject Tests subforum: look around not just for Praxis 5161, but for other states' tests of secondary math knowledge as well.
I found something called the education portal that I was using for a while. I thought it was helpful but I haven't actually taken the Praxis yet so I can't say whether it was successful or not. I am taking a break from studying because I got a fellowship. Teacher test prep allowed me to take a practice test and analyzed it for me. This was useful. Also, check out mooculus, an Ohio state calculus course online for free. Good luck!
I took the 5161. Missed by one question. My biggest issue was time management. Much harder than I expected. 5161 had a lot of "theoretical questions" such as which graphs are even functions? Or if you double the side of the cube, the volume will ??? It was all on the computer, no essay questions. most multiple choice, but some fill in the blank or select all that apply. I would suggest you go to a book store and look at the various prep-books for the Praxis. Buy the one you like the best. I would also suggest you buy the ETS test. I found it easier than the test, so be careful. I would also recommend doing other states tests or any other tests you can find. You learn math best by doing lots of problems.
CanIteachPhysic, I recently took the Praxis 5161 exam. How many raw points did you obtain and what was your scaled score? (If you don't mind sharing.) I'm just trying to predict my score.