First of all you need to edit the template to your needs, change the logos etc etc.
Then you need to slice the image into sections, using the SLICE tool in photoshop.
When you are happy with your slices, you can then export them using the SAVE FOR WEB option in photoshop.
This then converts the image to several images depending on how you sliced the .psd file and also creates a .html file.
You can then edit the entire .html file in a suitable editor and then upload.