I'm new to this stuff, too, so what are TACPs and JTACs?
TACPs: Tactical Air Control Party. Small unit (typically 6-8 guys per "Party") of AF personnel, "attached" to an Army Battalion. Can (and typically) sent down to lower levels (company and below) to move forward with that Army unit. Provides Command and Control of AF assets providing Close Air Support for that Army unit (and other services' air assets, as required). A RACP typically consists of an either a Air Liaison Officer (ALO) or senior NCO leading the TACP, plus some junior NCOs and airmen providing support (setting up the radio networks, running the equipment, etc.) The junior enlisted ranks are known as ROMADS (Radio Operators, Maintainers, And Drivers).
Attached link gives a good history of the enlisted career field
http://www.romad.com/history/history.htm
JTACs: Joint Terminal Air Controllers. Years back, when the dinosaurs roamed the earth, only rated aircrew were authorized to provide command and control of Close Air Support, due to the complexity of the mission. However, since the ALO numbers were very limited, and because the army leaders in the field wanted their ALOs close by to COMMAND the air support (i.e. request the assets and control the airspace), the AF wisely began to authorize our NCOs to also provide final CONTROL of Close Air Support missions (i.e. talk to the pilots on the radio to coordinate their attacks, ensure friendlies are identified and protected, etc.). They became known as ETACS (Enlisted Air Terminal Controllers). For a while, it remained that way: only AF personnel were authorized to provide Command and Control of Close Air Support assets. Other services were NOT authorized to provide CAS outside of very limited circumstances, sch as emergency situations (i.e. "drop that bomb now, or we're all dead here on this hill. And yes, my unit commander accepts sole responsibility for the consequences!")
Well, the Joint Fires Publication was reviewed after years of experience from Desert Storm, Iraqi Freedom, and Enduring Freedom showed it would be a good idea to allow sister service members to also provide control of CAS from the ground (the AF TACPs can't be everywhere at once, and CAS assets were in BIG demand!), as long as they were properly trained and validated as mission capable. Now, every service can have members qualified to control CAS in battle, as long as they have completed the course taught at Nellis AFB, and become certified as a card-carrying JTAC.
Also, are the pararescue guys and combat control both enlisted?
The TACP, Search and Rescue, and Combat Controller community all have a much higher enlisted to officer ratio. Just the nature of the beast, and very similar to army and Marine ground units.
By the way, the S&R and Combat Controller pipeline is combined during the initial phases of jump school, dive school, and a few other training areas. Its only after months of training do they split up to do their job-specific training (Air Traffic Control school for the combat controllers, battlefield medical rescue for the Combat Rescue guys...)