Can you help answer these questions?

Hi!
Thought I might be able to get some help from fellow Catholics in regards to Presbyterians. (pres-bee-teir-rians I can't spell!!)

My youth group is a Presbyterian one, and last meeting, I got into debate with the members in my group, about the differences between Catholic's beliefs and Presy's beliefs. Some of the stuff was hard to refute, because they don't belive anything unless is says so in the Bible.
So....to the point, I was wondering if anyone reading this could help give possible answers to their questions about the Catholic faith.
For example, they don't believe the Blessed Virgin Mary is any more special than any other woman, (DESPITE THE FACT SHE IS GOD'S MOTHER!!)
Also, they don't believe there is a Purgatory or a Hell. (The leader of the group said that, 'when you die, those who have accepted Jesus as their Lord and Saviour go to Heaven, and the rest just, well....they just......) !!
Do any of you reading this post know how I could refute their statements like the ones above? (*There isn't a Purgatory or Hell, and *the BVM is just like any other woman.)
Just thought I'd ask here, (cause your all Catholics!) because I am pretty sure that the debate will come up again, and I really need to be able to answer their questions really well.
Thanks!

Well, The BVM is the only person in history whom God deemed worthy enough to bear his son, and that alone makes her more special than any other woman.

For Purgatory - It is the name of the place where we receive our final purification before meeting with God
look here for some biblical proof
co1 COR 3:14-15

For Hell - It is plainly put in the Bible - if you reject Hell you reject the Bible, hence you reject God and Jesus Christ.

Hope this helps

Thanks Helena!
I looked up the text for Corinthians; it's pretty jolly clear isn't it?!!
Now I am just waiting for the opportunity to tell everything I have found out to the group....