The website is www.pro.gov.uk
There is a lot of information there but you want to go to the birth records. You can download the forms, which is quite handy for those of us living outside the UK. (I'm in Chicago, USA but all my family history is in England and Scotland, hence the subscription to Ancestry.)
There is a small fee to obtain a copy of the certificate but I think it's worth the cost. Also, you can pay with your credit card. I've done this several times in the past and have never had any problems.
Again, let me know if there's anything else I can help you with. Good Luck.