How did they leave it to you, by will? If so, are you an executor?
If a will was left, once probate has been granted the executor(s) will deal with the property left in the way specified in the will (it is different is no will was left).
A transfer of land (ie the house) in this way is called an assent. An mortgage will need to be dealt with.
This would then need to be registered at the Land Registry, forms and fees depend upon the circumstances and whether or not the land is registered.
There is a Land Registry Practice Guide
http://www.landregistry.gov.uk/assets/library/ documents/public_guide_009.pdf#search=%22execu tor%20dealing%20with%20land%22 and forms can be downloaded from the site which also contains details of fees.
If you are unsure I would recommend getting advice and help from the Citizen's Advice Bureau (www.ncab.gov.uk) or go and see a solicitor.