Educational and informational websites:
NHS - contraception
Sexwise - which contraception method is right for me
Contraception choices - contraceptive methods

Helplines:
National Sexual Health Helpline - Call 0300 123 7123, open 9am-8pm Monday to Friday
NHS - Call 111
Childline - Call 0800 1111, or visit childline's website. Free, confidential and open 24 hours a day, 7 days a week

Websites for all sexual health and relationship advice:
Brook
BBC radio 1
NHS - worth talking about
Rise above