I need to get a ITIN number and I have a question about supporting documents.

Since I am a student I need to attach I-20 along with the copy of passport, I-94, and driver license.

Question!

Every documents have to be notarized? Can I submit a just copy of the documents?

What other documents do I need?

The instructions of form W7 have a list of what documents you need:
http://www.irs.gov/pub/irs-pdf/iw7.pdf

If you send copies of those documents, you need to have them notarized. Your bank might offer free notary public services. Some post offices, UPS stores also offer these services (for a fee probably)

The BEST document to submit is a notarized photocopy of the passport page. That is the ONLY document that can be submitted by itself as identity proof.