have no idead how to do that.
I think it's time you picked yourself up a book.... or looked online for a tutorial on it (w3schools.com has some okay basic tutorials). You'd be amazed at just what can be achieved. Hell, even a table can be made with CSS... oh yeah... I went there.... TABLES CAN BE REPLACED BY CSS!!! HAHAHAHA!!
I design my layouts in photo shope... then it exports it into html.
then DW comes along and finishes it off the for the one two.
Reason #1 why I'll never respect any designer that does that.... dreamweaver makes some of the WORST code i've ever seen. Yes I started there, but I learned quickly that staying there wasn't for a real designer. I still design inside of a graphics program, then I chop up my images manually, and lay them into a custom CSS design. Then I know what works, what doesn't, and where I went wrong. Plus, it's half the fun of designing....
Get enough monkeys in a room and hitting buttons & keys on a mouse, and they too could make a design. Maybe not type shakespeare (only 35 letters so far, been running for 15 days), or make the best looking site, but by chance they could do it.
EDIT
Oh yeah... to answer the initial question:
I design for the target audience. Usually I know the general majority of the audience would be on a 15" CRT monitor running Windows 98 at 800x600 resolution. So I usuall code to a max width of 750 px. But then again, I also code for some larger audiences with a min width of 750px.... so the audience should determine the size.....