BF2S Forums Website help needed

Alright, lately i just started making websites, im new to the idea of making a layout in photoshop and im amazed lol.  anyways what size should i make my website? i tried 800 by 600 and when i opened the html file on firefox and ie , etc , the website just took a small junk of the screen even with my resolution set to 800 by 600.  How can i fix it so it takes up all the room on the browser?   

Also can i add html objects thru Photoshop or should i use dreamweaver or such

thanks!

-Maj Do