There are a few different ways you can sign up for the dole, or Job Seekers Allowance. You can sign up online here, or by phone, by contacting Jobcentre Plus on 0800 055 6688 (they are open Monday to Friday 8am to 6pm).
In order to complete your application, you will have to go for an interview at your local Jobcentre, you cannot do the entire process online or by phone.
In your interview you will have to agree to certain things in order to qualify for the benefit, this is called the 'Jobseekers Agreement', and includes the steps you will take to find work, and how you can improve your chances of getting a job. If you do not abide by this agreement, your Jobseekers Allowance may be stopped completely.