I too am relatively new to reloading and I can't stop! I've become addicted to it.
First thing you get used to is that there are 144 different powders!! DO WE REALLY NEED THAT MANY?! Find a powder burn rate list and familiarize yourself with some of the powders in your load data. If the load data has an astericsk by it, that is a load they feel had the best accuracy and results (with their gun and equipment).
So you try and weed out 140 of them . . . and go with 3 or 4 powders . . . just cause you can.
One rule of thumb I found interesting and helpful . . . "The heavier the bullet . . . the slower the powder". For all calibers.
Try this . . . pick one of your calibers, open all the load data you can find (books & on-line) . . .and cross reference which powders are used the most. It's helpful it whittling down the options and helps familiarize you with some of the language.
Then start working up a load . . . that's a whole other ballgame once you narrow down the powder choices.
Maybe it should go without saying, but set up your gear in a dedicated area where you don't get disturbed or distracted. And double check yourself through every step.
One screw up and "you could put an eye out"!!

I run a 180 gr. hornady sst with 55gr. of imr 4350 out of my mod.700 30-06 bdl and have 3/4 in. groups at 100 yds. Does great on deer and have killed many bulls with similar 180 grain bullets pushed by imr 4350.

I have had good luck with IMR 4831 in my 7mm Rem Mag (Remington 700 BDL Custom Shop Rifle) and use Win 748 in all of my .223's with consistent performance (7 different rifles...from a Rock River AR-15 to my daughters H&R single shot)...but as many have said, the bullet, rifle, barrel...and many other factors come into play. Doing your homework and taking your time are the most important.