You can get rules of thumb on the internet, computer programs that get you close, books like as said the Ultimate sniper by John Plaster. The US army sniper manual is on the internet, but nothing is going to get you the kowledge you seek like time doing it. Every rifle and every load is different, you need to find a load, bullet combination that works for your rifle and then head out and see for yourself what your package will do at different ranges in different wind and weather conditions. Keep a log book to help you keep track. I would recomend that you dope your bullet drop in increments of 50 yrds after 300yrds, just a suggestion. A quality Mil-dot scope with target turrets is a definately a tool that makes the long range job easier. I would recomend you put a good amount of dollars in this, it is money that will pay off in the long run. As for ranging you can teach yourself the mil-dot system or go the new and easy route of Laser range finders. It sounds like a lot of work to get into this, but it is only work if you make it work.....alot of us call it a hobby. If you have a range near by try and hook up with a few that do this, most are willing to show you a few tricks. "JUDGING" wind is something you learn with experiance, IE...watching trees, leaves, grass, flags, or mirage waves in your scope, now a Kestrel hand held weather and wind meter are the thing. I'm still old school here, but will probably go high tech soon. Hope this helps, if your an Albertan and close maybe we could hook up sometime and I would be happy to help ya get a start sometime.
Just an opinion