CPT code clarification

Do any of you know about CPT codes? I've read over a list of them, and I will post links to those lists, but being that I've never been trained in this I don't know what the primary or "important" ones might be - other than one: 90792 (Initial evaluation w/ medical services).

Any idea what kind of services are typically billed for particularly in a mental health setting? The psych-specific lists I've seen all seem to be psychotherapy-related, and we don't really get to engage in psychotherapy here as a standard so much as assess and perform medical management. Is there something I should focus on or look for?

http://www.wa.regence.com/provider/claims-and-billing/docs/2013-behavioral-health-cpt-code-changes-washington.pdf

http://www.ntst.com/compliance/cpt-code-changes-for-2013.pdf

Or, if you don't immediately know of the codes or know a source of codes: is reimbursement standard for each of those codes, i.e., as an example here, do all 90792 codes get like $172.33, etc? Is there a source somewhere that describes what each code receives as payment?