What do your various reloading manuals say?
If you accept that +/- 0.2gn of powder in NOT significant, then almost any pistol/shotgun powder will work.
Some of my most accurate loads with Unique came from a Pro Auto-Disk.
Try to weight 0.1gn and see how little that is. Then remember, that no matter what powder you use, some kernels will be ejected unburned.
I like AA2 for target loads and AA5 for mid-range to full power loads depending on cartridge.
As a beginner, don't start with Clays or TiteGroup--they both have some issues that a beginner doesn't need to worry about. One of the best "beginner" powders (no pressure spikes or other problems) is HP38/231. It meters well and is very accurate in many cartridges.
Right now, I think that I can do all my reloading for non-magnum handguns with AA2, AA5, and Silhouette. You really can't beat Silhouette in .40S&W for safe loads, IMHO.
If you want the high-priced spread of the day, try N320, N330 (excellent for 9x19), and N340. Any one of those can cover many cartridges very well.