Need help- WP cateogries should be sorted

Hey guys, I hope you can help me.

I need for my new website a plugin, which generates letter from A - Z, where I can click on. When I click that letter (for example G), then every article in the category, with the first letter G, will be shown. So that the articles are sorted by the alphabet letter, I can click on.

Well, my English isn't so good at all, so I don't know how to search for that. I don't find anything about that.
I hope you understand me.

Thanks in advanced.

PS: I'm a php, or css noob.

You'll get it.

Well, thanks at first. But I think that's not the right one. This plugin sorts my posts alphabetically, yeah, but I need a list of the letters, that I can click on.
There I can click on a letter and all posts starting with this letter will be shown.
If you don't know what I mean, I can send you an URL in a pm, where you can see that.

Anyone? :s

Thanks dude, exactly what I searched!