For a decnet quality protein supplement, DONT use holland & Barrett's gunk. Very poor Quality and its not worth any more that £5 per kilo to be honest
To get in good calories, have a Protein shake with water or milk and add a few glug of extra virgin olive oil. Stuff that comes in a dark bottle is best as it preserves the fats from oxidising and keeps them very healthy and packed full of goodness.
I find supplementing with protein and a quick carb source to be the best method of improving recovery (although i only run short distance and weight train so take that into consideration). Dextrose powder (20g) mixed with unflavoured Whey protein (50g) and 5g of green & blacks organic cocoa powder is brilliant. Some find that dextrose bloats them too much and prefer "WMS" (links to come).
Creatine supplementation works by replenishing ATP stores in the muscles. This is the type of energy burnt when involved in anaerobic exercise rather than aerobic...so its only useful if you are doing some sort of interval training involving sprints or weight training for example.
Cheap but high quality sources of supplements
www.myprotein.co.uk
www.bulkpowders.co,uk
I have only used MP although i know guys that like the service from BP
MP use a price matcher. Type in
www.bulkpowders.co.uk and hey presto.
Hope that has been of help.
SJ