hi louise, just been through all this recently as am buying a new house. best advise is to find yourself a good financial advisor (an indepent one who isn't attached to any lenders is best). We used one who was attached to our estate agent (although she worked independently to the agency). she was able to show us the best deals from over 200 lenders, without us needing to go around each one individually so saved a lot of time and effort for us.
Also, get a fixed-rate mortgage not a 'tracker' as tracker rates are connected to the Bank of England rate, and if the BofE puts its rates up - then your mortgage rate will go up too. If you get a fixed rate - then it won't change regardless of what the BofE rate does.
If you don't intend to live in the house for more than a few years, you should also consider an interest-only mortgage too as this will cost less in monthly repayments, and would give you a bit extra do buy furniture and do some DIY.
many lenders will consider lending you enough to include your fees, so mention this to your financial advisor.
good luck!