how do people make these?
coz when im older, i would want to be a web designer, and i thought this is a gd way to get started...?
ive made lots of normal ones. and a few div, but only from changing BG image and some overlay arrangements.
do they do it on dreamweaver?

Dreamweaver / Frontpage are but a few of the GUI tools used to create webpages.

The basics of webpages are in HTML.
Newer concepts split the content (what is said/shown) from the presentation
(the fonts, colors, and locations on the page using CSS.

Get some books and go for it.

BTW: Apache2 (a great webserver) will load onto your PC and you can
begin building and testing webpages without purchasing a domain URL

Personally I user Dreamweaver like Jobeard said, A good way to test the site you're making is to just go to www.freewebs.com and copy your HTML you made in Dreamweaver and create it there as a "Sample page" so people can test it

you can actually save new html pages on your PC (eg: newpage.html) and then
just dbl-click on the file -- your default browser will be launched to display it.

the trick (and also a good guide for real websites) is to use relative addresses
for all the graphics and links internal to the sited and full url address for only
exteral references, eg:

if the page has text with a graphic, the image tag would look like
and the pictures would all be in a subfolder images/

scripts and css files can be yanked in this same manner.

the only thing that can not be tested without a webserver is server-side CGI
or dynamic page generation stuff.