Starting off
First lets get our actions window open in photoshop. Just go to Window>Actions (the shortcut for CS4 is Alt+F9). Now you should see the actions window on the right hand side of the screen by default, go ahead and browse through it and get a feel for it. Now lets get some actions for you to use. Browse through the selections below and download whichever ones you like and save them to your computer, and simply drag and drop them onto the actions window in photoshop and place them wherever you like ( I prefer to make my own folder with my personal actions inside it to separate them from the defualt photoshop actions, to do that just click the new folder icon, which will create a new set for you to place your actions in).
Getting the actions
All of these action packs below are very simple color and contrast manipulations for photographs, but can be used on other images as well. You can take a guess at what they will look like by checking out all the different styles on the images.
Using the actions
Using actions is probably one of the easiest things to do in photoshop, and is similar to using the built in filters. All you need to do is open your preferred image, select the action you would like to try on it, and press the play button on the bottom of the actions window. If you dont like the effect of the action you use, just undo with Ctrl+Z and try another one. It is that simple. Here is a before and after I made with a simple color to black and white action I found on deviantart.com

In conclusion
It took less than a second to get from that color photo to a beautiful black and white photo. Actions are very easy and very effective for such a minimal amount of work. If you have a boring portfolio or just a bunch of images that you want to add a little bit of pop to, just go search the web for free actions, I guarantee you will find some that you absolutely love and will continue to use on most of your projects.
You might also enjoy reading:
Graphic Design Pro Action – Lighten/Darken
In this post I have provided a free download of an action that I made myself especially for my readers. This action makes it incredibly easy to lighten and darken certain areas of any photo without ruining its look. Full instructions and download provided.
Advanced Brush Tool Techniques in Photoshop
In this post I explain how to use brush styling in photoshop to create some awesome effects. This is aimed at beginners, but also has some more advanced techniques too. This is a must read for anyone looking to improve their photoshop skills.
This is a wonderful tutorial. I read it 3 times and got fantastic results. Im going to throw up a link to it on my site.