Quite a lot of detail to provide in a forum post. Steve Lopez has done a fine job covering this in many of the chessbase articles.
http://www.chessbase.com/download/index.asp
The basic stuff is covered in earlier versions of chessbase, so be sure to hit those articles sequentially to get a tour of many of the features that carry over to CB10.
I don't know the difference between chessbase reader and other chessbase versions, but the main feature you want to use IMHO is "selection to book," which is something like magic.
Open a database, choose a certain amount of games, choose the games you like, click on "selection to book" and voila, you have an opening tree in .ctg format. It's so easy to browse through the lines and see statistics. You can make various operations on that opening book, like marking moves with "main move" or "don't play in tournament." which changes their colour so you recognize them quickly.
Fur further statistics on particular moves in the opening tree, right click on the opening book window, select properties and click "show statistics." It will show W/L/D ratio of every move.
May be I am too dumb for not figuring out this myself, but since there may be others that know how to use chess software may be they can help. I have a chess base reader (not chessbase 10) which came with Megabase 10 and no other software for now.
My question is how do I mark games for future reference? Lets say for King's Indian I liked a set of games and want to refer to them in future is this possible in that? If not please let me know what's the workflow that tournament players use on their computers in their opening preperation. I can spend more $ if need be. Also I am getting Fritz10 that I got cheap on ebay.