there are a zillion threads on here on how to use hcg, dosage, etc. do a simple search.
you will need slin pins, bac water, vials, etc to mix it as well... and obviously you need to put it in the fridge so it lasts for a month or 6 weeks
blasting means you run it before your pct. usually during that window while your juice esters are clearing so that your nuts/LH/HPTA plump up really good... it will speed up recovery rather than going into pct with raisin nuts and then depending on pct to do too much for you.
mcg's means micrograms and it has nothing to do with hcg.. usually people will use IU's with hcg. 1000iu's for example.. if it comes in 5000iu bottle, then 1000iu's will be 1/5th of that .. so you would mix it and inject 1/5th of it at a time during yoru blast
other guys like to use it throughout cycle at low doses then blast it. the way i do it is i use hcgenerate during cycle, then use hcg AND HMG to blast ahead of pct. after that my nuts are nice and plump and my recovery is like 75% faster.. its amazing. other guys will run nothing ahead of pct to plump the nuts, go into pct with raisin nuts and then complain that their pct sucked. well had they plumped their nuts ahead of pct they would have had a much more successful pct and recovered very fast. its all about having a soft landing vs. hard landing.
so the bare minimum would be hcgenerate last 4 weeks of cycle, HCG 1000iu's every 4 days while esters are clearing, 2 shots of HMG mixed in there, and then run your pct which can be a little clomid, DAA, phystoserms/unleashed, etc. if you don't fully recover after that then you screwed up somewhere cause that is the way i do it and i recover fast everytime.
also during cycle you should be running an AI is applicable depending on if the stuff you are running aromatizes. dont be going into pct with high estrogen and expect things to go well for you. and also don't go into pct killing off all your estrogen either using nolva or high doses of clomid and expect your dick to work. you want estrogen, but it has to be the RIGHT amount. not high and not low.