all my links are not working,.even if you go under book reviews,.if you hover over one of the book titles it neither underlines nor changes colour, before l worked on the CSS it did but not anymore.
The CSS you added won't affect whether a link works or not.
I think perhaps what you did was underline some text and change text color in the editor, but you didn't make those things into links. To check this, let's look at a specific example.
Look at this page: http://miriamtereck.com/2012/02/06/10-keys-to-positive-thinking/
At the top of the page, there is some red underlined text that says, "Napoleon Hill’s Keys to Positive thinking, 10 steps to health, wealth and Success – Michael J.Ritt."
That is not a link, it's just text you've made red and underlined. Instead of doing it that way, try following this guide first: http://en.support.wordpress.com/links/
And then use CSS to format all of the links in one rule.