1) What kind of fluid does it need... MTF or ATF
I went to checker auto and told him I had a small leak and wanted to check and top off my tranny fluid. he told me that almost all newer cars had ATF in them. I bought a quart and didn't check/add any of it yet. I thought someone said to only use MTF is this true?

2) I want to check it, how do I do this- I didn't see any dipstick, I know there is another way but I've never done it.
I could only find out how to change it in the sticky.

3) Do I have to totally change the fluid or can I add (even if I don't know what kind is in there)

p.s. I think the leak is coming from the gasket for a sensor in the tranny

Pics: http://www.cardomain.com/memberpage/383852/2
I already posted but didn't get a good answer about this.
any help would be greatly apreciated

Do not use ATF, only gear oil.

There is no dip stick to check the fluid level. If you read the how to for changing the MTF then you know how to check it. Just remove the fill/check bolt and stick your finger inside, You should be able to feel the fluid. Try to have you car as level as possible when doing this.

You can top it off with a different brand fluid, it won't hurt anything. Just make sure it's 90 weight

Add a 75w-90 or 80w-90 gl-4 gear oil and you'll be fine. Like mike said there is a fill bolt on the side of the tranny and the level should be to the bottom of the bolt hole.