how to finish an attic?

[bill weathersbe]

I am using pro 8, if pro 9 has better features for this problem please let me know. I am trying to design a room in a attic space that has 12 12 pitch roof
which has good space for the addition. I can not figure out how to get to the attic space to change/design it. Or should I try to change a second floor to look like a finished old attic space.
I have tried that but i did not have much luck, any ideas?

Thanks, Bill