Offer accepted on a house - renovation tips please

[milge]

I have had an offer accepted on a house which is in a complete state. It is structurally sound, but needs lots of tarting up/TLC. It has been rented for 8 out of its 10 year life. Its a 4 bed detached with 2 ensuites and a family bathroom, living room, dining room, kitchen, utility and study.
How much do you think I will need to budget for the following:

Painting it all
curtains
carpets/laminate
3 bathrooms/ensuites
new kitchen
Decking/patio to the garden.

We are not a practical family, have no members who are good at DIY or are tradesmen, so I feel a bit at risk of being ripped off.
Anyone done something similar??

Agree with not paying ANYTHING upfront apart from materials.

I still tell people to ask if they can see examples of work carried out by builders. Nearly every builder I have ever met will have worked on their own house or family/friends who will be only too please to let potential customers inspect their (tradesmens) work. I wish this would become 'standard procedure' cos DH would get all of the work in Essex

Thanks for all the tips at £20k excl kitchen for a 2 up 2 down. The Sarah Beeny book looks great, have added it to my amazon basket, thanks Jackie.
Am beginning to feel slightly sick at the thought of it all, and had I not just stumped up £400 for a valuation, I would off to a new build development and buy a nice shiny new house ( with a long list of snags.......)