The State Dept's current "visa bulletin" lists wait times based on priority date and chargeable area (the intending immigrant's nationality). A GC holder sponsoring a spouse falls in the F2A category, which is current for Jun 2003 for most areas except Mexico.
http://travel.state.gov/visa/frvi/bulletin/bulletin_1360.html
If you are already married, its going to be very hard, or (more likely) impossible for her to be approved an F-1 student visa since she has already demonstrated immigrant intent. Another way she might legally stay in the country is to seek an employment based H-1 visa, but these too are hard to get due to 65,000/yr cap. Finally, there is also the E-3 investor visa, but that requires significant cash outlay, and starting a genuine business etc.
The first step you need to take to secure a priority date (PD), and hence start the 5yr clock is to submit an I-130. If you naturalize prior to the PD becoming current, you can upgrade the petition to immediate relative (IR) category and eliminate the remainder of the waiting time.
Finally, I would mention that your wife needs to be careful not to accrue unlawful presence, as this could cause complications further down the road. I can elaborate more if you aren't already familiar with the 3yr/10yr reentry bans, and the conditions under which unlawful presence can be forgiven.
