There is a huge difference between loading for high-V rifles and medium pistol cartridges, and many of the things needed for rifle loading are nearly irrelevant iwth ordinary straight-walled pistol loads.
NRA has reloading courses available, and will sell you a good book on basics.
Program Materials Center - Product Details
NRAInstructors.org - Portal for NRA certified Instructors, NRA Education and Training
A knowledgeable teacher or mentor will save you a lot of time and grief. For safety's sake,
it is most important to learn what NOT to do. There is a lot of misinformation and outright dangerous loading data floating around on the internet that may or may not be safe in YOUR gun.
For example, if 5 or 6 shooters at the IDPA club tell you they are loading 4.4gr of HP-38 under a FMJ 124gr in 9mm Luger, it would be ridiculous to go through the whole routine "working up" this load. A quick
check of a couple good manuals shows this load to within recommended range, and you have to "make power" to shoot IDPA.
However, if someone tells you he uses HP-38 to make MAJOR POWER in 9mm, just walk away and ignore anything he says. Why? WAY OVER any recommended load, and possible KABOOM!
The mechanics of loading are simple, but unforgiving. People accustomed to following directions and paying attention do well, but some people just shouldn't reload--like some you wouldn't want in EOD.