Gather all of your and his paperwork- at least 3m bank statements, work contracts, copies of credit card bills etc.
Book and visit a free whole of market Mortgage Advisor who will help work out how much you can afford to borrow. Show them proof of deposit.
Look online at the sort of properties in the area you would like so you know roughly how much these cost.
Once you know that you can get a mortgage, that you have affordable monthly repayments (aim for max 20% of income), and that you have the deposit you need, start booking in some viewings.
Once you find a property you want to spend your money on, work out how much you want to pay maximum. Offer under this with a view to paying up to this. It helps to have an Agreement in Principle from the Mortgage Advisor before making an offer.
Wait til the offer is accepted/declined etc and once you have an offer accepted, reach out to a local conveyancer and tell them you would like to purchase a home and can they do the conveyancing.
They will then take it from there in terms of searches etc. You book a survey and pay for it. Depending on the outcome of the survey you may choose to renegotiate or pull out.
Eventually when everyone's happy, you discuss a date for the house to become yours.
Contracts (legal agreement to buy the property) exchange usually up to a week before the house bec9mes yours. Money moves around on the day it becomes yours.
Always insure the building from the day contracts exchange, as even if it burns down the next day you have to buy it.