Reading greens can be tough. It really starts as you are approaching the green. Try and get a feel for what the terrain is doing. Get a feel for the general slope of the green.
The old school way I was taught was to imagine you are dumping out a bucket of water. If you did so, where would the water run to. One of the things Aim point does is have you straddle the target line and try and feel the variance of the terrain in your feet.
One of the things I like to do is to try and find the apex of the break, then feel like you are putting to the apex.
As far as speed goes, you really need to confirm if you are putting uphill or downhill, obviously it makes a big difference. Also, spend some time on the putting green prior to playing. Most practice greens are similar in speed to what is out on the course. I went to a Teaching seminar a few years ago and they really made an emphasis on what distances to practice from. Statistical data shows we should practice our long putts, 30 to 40 feet and our short putts, 3 to 5 feet. These are the most common areas that golfer putt from.