i used it once.
set up the tank with filters and heaters. add water, dechlorinate, wait until it comes up to temperature and make sure all equipment is working properly. make sure you have test kits for ammonia, nitrite, and nitrate, and equipment for water changes (tubing and a new clean bucket or a python).
give this whole process a day or so.
the next day, go out and get your biospira. buy it, bring it home, put it in the fridge. then go out and get your fish. acclimate fish slowly to the new tank - the completely clean water is going to be a big change from the LFS water, and you don't want to shock them. you can use your water-changing bucket for this. put the fish in the bucket, along with the bag water, and add a cup of the tank water to the bucket every 5-10 minutes, until you have 1/4 LFS water and 3/4 new water. then net them out into the tank.
once they are in there, get the biospira and shake it up really good. pour 3/4 of the package into the tank. fold up the package so no air is in there (using a paper clip keeps it folded over), put it in a ziplock/sandwich bag, and back into the fridge. saving a little bit of it works as a back-up system in case nitrite-to-nitrate conversion stalls out.
you can feed the fish, but, as always, be careful not to overfeed. after 48 hours the bacteria will have left the water column and settled in the filters and all over the tank. at this time you can test your water for ammonia, nitrite, and nitrate and see where the cycle is. bio-spira does not usually immediately cycle a tank. it will reduce the time to 1-2 weeks instead of 6-8 or more. keep an eye on the water parameters and do changes whenever ammonia or nitrite get up to .25. once you get 0 ammonia, 0 nitrite, and visible nitrates, you're cycled. if ammonia and nitrate are both at 0 and nitrites keep rising, do a big water change and then add that last little bit of biospira you saved in the fridge. give it a day to work, and then continue with water changes as necessary. after the cycle finishes, weekly water changes as all you need. keep nitrates under 15-20ppm.