Implementing a quiz system through MVC

Hi there folks !
I am trying to build a quiz system in rails and I was pondering on
how can I implement it right,
since I am new to rails and have no clue about routes what so ever Im
a little stuck with the project.

I will explain a little about the quiz main features so you could
understand my mental pazzle:
I have questions stored in a database, divided by categories, which
are also stored in a database.
I have 3 types of test formats:

1. practice(in which the user have no time constraint what so ever):
1.1 by choosing quantities of questions from each category.
1.2 by choosing a category

2. preconfigured tests (w/ time limit)
2.1 admin preconfigured quantities of questions from each category.

3. random questions (w/ time limit)

Now the way things work right now is that I have a test controller
with 3 actions(as you can guess by formats of test).
My problems started when I tried to let the user pick a category in
practice, it linked the route the wrong way, as a format of a
file( f.e .xml) instead of doing "practice/1" it printed "practice.1".
I must mention that I made changed to the routes file and added
map.resources :test, :collection => { :real => :get , :practice
=> :get, :prebuilt => :get }
so I got these nice helper path functions and when I try to link a
category for the user to pick, with the path function, it makes the
link like I've mentioned.

If you can offer me some guidence and/or correct me with the way I
implemented the system I would be thankful,
Shlomi.

By the way, I know my message is a bit odd, it's due to the fact that
I am a bit confused.