OK, I'll try and keep it interesting.
The A-10 was born out of the dismal experience of ground support during the Vietnam War. Alot of study was put into a plane that was specifically designed for close air support of ground troops. High speed and air to air combat were not really considerations. Survivability, load carrying capacity, and accurate delivery were key. In fact, the weapons systems were created to do the job, and the plane designers built the aircraft around the weapons. Since the primary battlefield was to be eastern Europe to defend against the USSR's overwhelming advantage in tanks, a special gun had to be created to destroy them. The typical aircraft gun at the time was the 20mm. The shells were not powerful enough to penetrate the tank armor, so a larger, more powerful round had to be developed. The CAS (close air support) plane would get a 30mm (1.25") gun.
Two company's put forth designs out that were flown against each other - IIRC it was Northrup A-9 and the Fairchild Republic A-10. The A-10 design proved much more capable, and was chosen for production. That started in 1975, with the first birds being delivered in 1976. Production ended in 1983 after about 750 planes were built.
Davis-Monthan AFB in Arizona was the main training base, with Myrtle beach AB in South Carolina was the first active flying base. They got the earliest batches of planes. As I recall a hurricane went through the area in the 80's, and the Myrtle beach was so damaged they decided to close the base down rather than repair it. All the planes got sent to us in Arizona. All I remember is how grody and rusted those birds were - the salt sea air and obvious lack of care was woefully apparent!
The GAU-8 gatling gun is the main attraction of the Warthog. Capable of firing 4200 rounds a minute (on high speed) it could obliterate any tank. The armor piercing shells were made of depleted uranium, very dense and turning into a fireball inside the tank after the friction of penetrating the armor sets it off. Development of the rounds and gun was tough. The early projectiles had a smoky burning powder, and the gun put out so much smoke that they found in early tests the engines would get starved for air. Plus the pilots couldn't see anything! So cleaner propellants were developed. Also, the recoil from the gun was so strong (I heard) the planes had to be flying at least 300 MHP and descending or the plane would slow down enough to stall. Typically now most bursts of the gun are kept to a few seconds at most to prevent this. And it wasn't a problem - just one of the shells hitting the tank does the job!
The second main weapon is the AGM (air to ground) 65 missile. Using a visual camera system, the pilot can "see" what the camera in the missile sees and locks it onto a target. Once fired, the missile will follow the target. Even if the tank is cruising at 60MPH it'll still get toasted!