I think I have already gave my $0.02 on the original cover in some other thread, but for the new one with the girl:
Front:
1. The girl looks like you just googled for a picture and just cut her out and pasted it on there. Find a better picture to use (do not use google!, go get some quality pictures that yeah you will probably have to pay for).
2. Do something with the background. Like I said a pixelated girl pasted on top of a blue background is not interesting at all.
3. Play with the text, it seems way too boring and amateurish. Instead of just doing a drop shadow and throwing it on top of the picture, try to incorporate at least some sort of design work into it. Shrink the authors name as well.
4. For the inside flap, your prices are screwed up.
Back:
1. Either do something with that picture or get rid of it. Again, it looks like the result of a google image search and you just pasted it on there. Hell, the pic would be fine if you found some way to work it in so that it doesn't look like you just threw it on there.
If you are actually getting this published and expect to make money off of it you have a lot of work to do, no offense. Have you thought about forking over some cash and having someone make this for you?
edit: and why the fvck does my age/sex matter?