Create a Standard post page

Hello, this is my first post in here and i have some doubts, please help me.

For a better understanding,im making a sharing content site (images and audio) and i need a way to standarize the post page, because contributors can dispose the material has they want, ie: one can put image up, other down the comments,etc.

As an open site, im developing an entry page out the wordpress administration scheme (to make newbies an easier experience).

Question:

What is the php file that manage the structure of the posts in wodpress, its possible make what i want?

If anyone gots information or a link please give me =)

Thanks

PS:Sorry if the forum had a thread with this topic. Sorry my english