Graphics
Once again "A picture tells a thousand words", But unless your site is an art display, keep your images to the minimum. and have a checklist before you include an image:
Is it necessary ?
Is it the right size ?
Does it convey the right message ?
Is it in the right format?
Images are the major cause of low to load pages, large images take time to load and slow down your visitors journey, will they wait for that one image or will they pass over to a faster loading site?
Most people now have a digital camera, so it is quite easy to take your own photo's, otherwise you will have to buy stock photo's or find a source of free images. this can be a task in itself, if your subject matter is somewhat diverse. Do not forget with a little patience and a good graphic's program you can make your own images, and there are thousands of tutorials for graphic design on the web.
an
animated gif image
A great resource for free images is Stock exchange at http://www.sxc.hu/
you can always find local photographers and get some free images, just by putting their name under their images.
Types
there are three main types of image use in web design they are:
jpg ( or jpeg)
this stands for Joint Photographic Experts Group. this method compresses the
graphic to the smallest possible size, whilst holding onto the maximum colour
range (normally 16 million colours).
gif
stands for Graphics Interchange Format, this method is used for animations and
can support transparency, but the downside is it will only hold 256 colours.
png
The newcomer, of the three, png stands for Portable Networks Graphics, being
similar to the gif in that it supports transparency, it also uses a compression
method that means the less number of colours used the smaller the size of the
file. Also where as the gif has absolute transparency, a png uses an alpha
layer so you can choose the level of transparency, although IE6 does not support
png transparency, IE7 now does.
adding
depth with the use of a drop shadow
Depth
To give depth to a page you can use drop shadows, and borders to your images, also to your text divs as well, with the use of your css styling you can add a background colour or image to add depth and texture to the div in which you will place your images.
Remember also, images can lead the eye to and away from the next place of importance on your pages. once your pages are created get someone, to check them over and be critical and honest with you.