Here is everything you need to know about pocketing shots, and there will be people who say it's not possible, but the following is fact:
Every makable shot that is not straight in will fall under the category or 15, 30, 45, or 60 degrees. Based on the size of the table and the size of the pockets a ball hit with no english whatsoever will pocket a ball with one of the above degrees.
You can pocket each of the above by AIMING the following way, again I say AIMING, not actually contacting the ball at these points, but rather AIMING at them
Straight in simply aim at the point on the cloth where the bottom of the object ball touches it, much easier to look at that point than the center of an object that is a solid color.
15 degrees, aim the center of the cue ball at a spot that is 25% away from the edge farthest the pocket, simply put draw an imaginary line down the center of the ball, then down the center of the half you are aiming at.
30 degrees, aim the center of the cueball at the edge of the object ball farthest from the pocket
45 degrees, aim the 25% point on the cueball (find it the same way as above) at the edge of the object ball farthest from the pocket.
60 degrees, aim the edge of the cueball at the edge of the object ball farthest from the pocket.
You can find exactly what angle you are looking for by using the diamond on the table and a bit of guesswork. There isn't a chance I could explain it without you looking at the graphs I have, suffice to say you if you look at the shot and 45 is too much and 15 doesn't look like enough then it's probably 30, you will get good at reading the angle after just a few hours.
Practice this until you can pocket balls at ease and then move on to position play, which for that I recommend getting hold of a game Kim Davenport (I think) created called target pool. It covers almost every shot you will encounter and give you a way to track your progress, but most importantly it really focuses on speed of shots.
Good Luck
PS, I am not interested in arguing the angles involved and won't, I know this is fact. Please don't come in here and say "well what if it's just a bit less than 45, wouldn't it be 40 degrees", the answer is no, buy a protractor and figure it out for yourself.
Get my e-mail from Jack if you want to talk more about this or there is something you don't understand.