There are so many tips and tricks and ways to do things, first tip is not to get confused by them, use the method that suits you best and gives the result you're after.
Layers
Hopefully you've already discovered that layers are very useful, you can make all your enhancements and manipulations on seperate layers thus preserving the original image and making it easier to go back and alter things when you change your mind.
A quick way to make multiple visible layers unseen is to left click the mouse button the usual way on the first layer and drag the mouse button down over the of layers before you release the button. The same method works to turn layers on too.
Saving files
Save regularily and often, you don't want to lose all your work.
Save your photoshop file as a .psd file (or a .tif) so it keeps all your layers seperate so you can come back and do some more work on an image some day and Save As other file types as you require for printing.
When saving to print at your preferred lab save your images in sRGB format as most labs use this format (ask professional labs). You only have to set it the once and it will then be the default. [CS2]
Edit>Convert to Profile - Destination Space>sRBG
Composition - 'Rule of Odds'
'Odd numbers are better than Even ones in photography.' By displaying an odd number of objects, there is always one in the middle that is "framed" by the surrounding objects. If you haven't already tried it, give it a go. Also think about it when you are cropping your images too. Take a look around at images with multiple subjects, see if they work. Three objects in an image is particularly good, five, seven or more can work but you risk clutter
Composition - 'Rule of Space'
Allow the subject(s) of an image space to move. For example, leave white space in the direction the eyes of a portrayed person are looking. Or add whitespace behind a runner rather than in front of him to indicate movement. Give animals somewhere to walk into, try giving more space in front than behind.
Model Releases
nWant a model release or want to make your own, click here to have a look at the ones on the VAPS website and get some ideas.
Red Bubble
Red Bubble is an online Art gallery based in Melbourne. Upload your files to sell online or to display in your own on line gallery.
Make T-Shirts, Greeting Cards, Posters, Canvases etc. from your work. Keep them for yourself, or offer them for sale in your portfolio and gallery. They take care of the payments, production, packaging and shipping, giving you more time to create something great. Red Bubble makes money when you do. To find out more click here.
Buying a new digital camera
If you're in the market for a new digital camera have a look at the Dpreview website, where you can compare cameras and features; read reviews written by owners of that model. You can discover benefits and short comings before you make your important purchase.
The Gimp
The Gimp is a photo imaging program gives you the power to enhance and manipulate your images and is a cheaper alternative to Photoshop. Find out more on their website.
Picasa
Picasa is software that helps you find, edit and share all the pictures on your PC. Every time you open Picasa, it automatically locates all your pictures (even ones you forgot you had) and sorts them into visual albums organized by date with folder names you will recognize. Picasa also makes advanced editing simple. Picasa is free to download.
Australian Digital Photo of the Day (recom by David)
Free registration allows you 5mg upload of images, any member can give feedback on images. Images become part of a competition and a winning image can be published in the magazine. The sites forum offers much information and assistance. Membership is open to Aust only.
Passion for Pixels (recommended by Tony)
This is a photographic site, you can become a member and you are able to take part in their competitions and more. Have a look at the site, it has a lot going for it. One section has images submitted by members who give permission to others to enhance their images, the images are all displayed and you are able to see just what is possible with imaging software.
DCViews (recommended by Brian Paatsch and VAPS)
Just starting out in photography and want to find out more or want to review the basics, then check out this website.