There’s a lot of info on theme development at the Codex:
http://codex.wordpress.org/Theme_Development
Note that themes deal with WP templating, and anything that works outside of that should not be included with a theme’s files. If you have separate html/PHP documents, they should reside where they normally would on your site.
In my CSS, Do i have to set the background-images embedded in XHTML or I can set my background-images on my style sheet?
As was mentioned, all of this information is in the Codex.
The style sheet controlls the presentation of your site. If you want consistently embedded images in the background, use the style sheet.
For almost all background images, you should use the style sheet. It is called style.css and located in your Theme folder, which you created, or should have, as you explained in your original post.
For more information on styling and fixing every part of your Theme and site for beginners, see http://codex.wordpress.org/WordPress_Lessons
I copied all my files including the stylesheet into the wp-content/theme folder but i get a message saying: “Broken Theme. The following themes are installed but incomplete. Themes must have a stylesheet and a template.” I created a stylesheet and copied into that folder, everything is there but i still get message. Could anyone help me?
They all go into the /wp-content/themes/yourthemename
folder.
Have you read the documentation links provided? It goes through this step by step.
Here is another: http://codex.wordpress.org/Using_Themes
Follow the instructions and you will have all the answers.
I did exaclty what the documentation says but it still doesnt work. I even deleted and uploaded again.
Obviously something went wrong. Do you have the minimum basic templates in your theme? Does your stylesheet have the proper heading?
Well, yes it does. I dont know what’s going on! THis is how i started. I created another folder and called design01. Also inside design01 folder i created another folder called images for my images. I copied all the files from the default theme into design01. I changed all the php files according to my needs, although i didnt change any php code only the html tags. I created my own style sheet and called it styles.css and saved it into design01 folder. After all that, I uploaded the design01 folder into wp-content/themes folder. I really dont know what i did wrong.
well… i deleted, uploaded again and worked! I dont know what happened!