Once you have your C.V. ready, try the websites for the companys you are interested in, they will normally have a "Join Us" or "Careers within xxx" link or it may be in the "about us" section of the site.
Here is a list of some of the sites where you can find jobs or register with an agency.
If any of these links are broken or if you have suggestions for other good advice or links, please let us know: webmaster@my-advice.com