There is a free website called FAMILYSEARCH.ORG which is worth a look.
On the Family Search website you can find information about Family History Centres around the country where you can get free advice and access to lots of websites.
I should point out that Family Search and the Centres are run by the Church of Latter Day Saints, otherwise known as the Mormons. I know this might bother some people, but you don't have to be a member of the church to use their centres, they are incredibly helpful, and there is no religious pressure at all.
I have used the Centre at Reading in the past, and it has been really useful.
rfhc.org.uk
There are also other paid-for sites such as GenesReunited and FindMyPast.
All these sites have different information and it is worth looking at each one to see what they hold.
You should also see if there is a Family History Society or Club in your area. There are loads of these, and they often have websites which are very useful.