Question on commenting an analyzing games

I was going to post a game here, fully annotated about my thoughts on the game, but this program called "chessbase light" wouldn't let me save it.

 I've tried doing comments through arena, but I can't figure out if there is an option to. In your guys opinion, what is the easiest and free way to add your own comments to a pgn?

Also, is there a way to get an engine to go through all the moves and assign a value to each move, or point out where blunders or tactical opportunities were missed? Again I tried this with arena, but i can't figure it out. There is an automatic analysis button, but it won't point out blunders, just gives numbers.

I know someone must know how to comment on a pgn and how to have an engine look for blunders..

Hi,

I use Chessbase or Fritz but they are not free, however, you can enter moves and add notes to your game on here

The numbers you see on your engine are the + and - in a position, so if whites move has + 2.5 or similar it is about the equivilent of 2 pawns up, or at least a very superior position.

I hope this helps.

Thanks sirness.