I wouldn't suggest a MAC tho
It's damn expensive. I would suggest buying a nice quick guide to CSS and HTML. Get used to work with more and more browsers. Making it work in Netscape 4.7 means it will look the same way in ANY other browser (at least these're the results of my personal observations). Whatsoever, I use generally Firefox and almost try to never launch IE, but it happens that oversized pages are showing up in IE, which is a little bit odd. Try to keep the width up to 760px MAX, adding 30px for margin and/or padding will give you a total of 790px width, which leave you with 10px to play with
Don't forget that putting a larget image (width 820px) will, nomatter the table settings, resize your table, but most probably you will notice this yourself.
I suggest you get yourself Firefox it has a great webmaster extension that have tons of useful options as - show image width, tables width, objects width, resize window to 800x600, etc.