Well you will need a pattern to start with. Most large department stores will have fabric departments with pattern books to look through.
The ladies there will advise you on the amount of fabric, interfacing, buttons, cotton, pins, scissors, etc that you will need.
If you have never sewn before you will be better getting a plain fabric rather than patterned.
The patterns come with instructions on how to lay out the fabric and your pattern.
Oh and you will need a sewing machine unless you are very, very good at doing very very tiny stitching.
I do not know if there is a website for this, but there must be one somewhere, so keep looking, and good luck.
Trishxxxxxxxxxxxxxxxxxxxxx