This recipe is taken from the BBKA website. Full PDF file is found here

INGREDIENTS:

3 - 3 1/2 lb. honey
1/2 oz. citric acid. 1/2 tsp. tannin (or 1/2 cup black strong tea).
2 tsp. yeast nutrient. Wine yeast (Maury yeast has been specially
selected for mead but a General Purpose Yeast will be suitable).
2 tsp. yeast nutrient & 1/4 tsp. yeast extract (e.g. ‘Marmite’) to provide vitamin B.
Water to 1 gal. (S.G. approx. 1.100 = potential alcohol 13.4%)

METHOD:

You can obtain your equipment and ingredients from any wine making supplier.

Warm the honey in three times its own volume of water, stir to dissolve (avoid burning the honey), bring just to the boil and simmer for a couple of minutes. Remove the scum. Do not boil fast as many desirable substances will be evaporated, causing loss of flavour and bouquet.
When cool, transfer to a 1 gal. glass jar (demijohn) previously well rinsed with hot water. Bring the remaining water to the boil and when cool add to the dissolved honey. Add the yeast, nutrient, tannin and acid. Fit an air lock (or plug the neck of the jar with cotton wool) and leave in a warm place.
When fermentation is complete (when there are no more bubbles and it has begun to clear), siphon using a length of plastic tubing (or carefully decant) the mead into a clean jar leaving the sediment behind.
When another deposit has formed, siphon again.
When it no longer throws a sediment and is clear, bottle. If necessary, filter or add wine finings.

The above recipe should produce a dry mead containing about 13% alcohol. If the finished mead tastes rather sweet, delay bottling until you are sure fermentation has finished to avoid burst bottles. A medium mead would need about 4 lb. honey and a sweet (or sack) mead 4 1/2 lb.

Sultanas give extra flavour, body and smoothness to mead and nourish the yeast. Rinse 12 oz. sultanas in warm water and chop or mince. Ferment on the pulp, stir daily, and strain after 10 days.

Your mead will probably be drinkable after a year. Having made mead, don’t be impatient to drink it - there is no comparison between young mead and the matured article. Brother Adam of Buckfast Abbey recommended maturing mead in sound oak casks for a full seven years before bottling. I have never achieved such perfection. At least hide a couple of bottles to mature and make some more. 5 gallons lasts almost twice as long as 1 gallon!
And of course, if you are a beekeeper, you will enter a bottle of mead in the National Honey Show and your local Association Show.

If you are a beekeeper and wish to use the honey remaining in cappings, you need to measure the amount of honey dissolved in your liquor. The old method was to float a new laid egg in the dissolved honey and when only a piece of shell the size of an old sixpence was showing, the amount of honey was correct. Nowadays, one can purchase an instrument called a hydrometer which is easy to use and much more reliable.

Place the cappings in a suitable container and add cold water. Stir to dissolve the honey, allow to stand a while and then strain. Take a hydrometer reading and adjust with honey or water to give the required starting gravity. More honey will increase the specific gravity, more water will lower it. Proceed as in the recipe above.

2 lb. honey in 1 gal. gives S.G. 1.060, potential alcohol 7.8%.
3 lb. honey in 1 gal. gives S.G. 1.090, potential alcohol 12%.
4 lb. honey in 1 gal. gives S.G. 1.120, potential alcohol 16.3%.

Dry Mead: Starting S.G. 1.085-1.105. Finish S.G. 0.990-1.000.
Medium Mead: Starting S.G. 1.105-1.120. Finish S.G. 1.000-1.005.
Sweet Mead: Starting S.G. 1.120-1.130. Finish S.G. 1.005-1.015.