When you have found the job(s) you are interested in, scroll to the bottom of the page where you will find a red button on the right-hand side, stating "Apply". This will take you to a log-in page, where you can log in to apply to the role(s) you are interested in.
If you haven't already registered on UKCIl, please click the "Sign Up" button - next to the "Apply" button - and fill in the corresponding details.
While it should take no longer than 10 minutes to create your profile, do take care to think about yourself and the types of roles you are applying for - help the prospective employer know a little more about you by giving some details on, say, your personality.
Once you have created your profile, you'll be able to apply for the role(s) that you want and will be sent notifications if other roles could apply to you.