multiple pages multiple layout

Hey,

I am a novice in WordPress. I have installed wordpress and using twentyten template.

I want to change that to my own html.

Can anyone direct me to good resources where i can find information about how to put in our own html in WordPress theme.

Also, i want to show different page layout for different pages. For example, stats page will have different layout (header, footer will be same, but sidebar will change) and about us page will have different layout ?

How can i achieve this ? I know there is something called templates with which i can do this ? Can anyone direct me to some good resources please ?

Thanks
Zack