Centre for Sustainable Energy (CSE)
This site has many downloadable info sheets and videos around energy saving, including one on central heating controls and one on DIY draught proofing.
Centre for Alternative Technology (CAT)
The Centre for Alternative Technology offers advice on a range of topics including energy saving and green renovation.
How to make your own draught excluder
The National Trust (NT) has put together a very simple set of instructions on creating a draught excluder for your home.