The total amount needed will depend on how big your batch is and the size of the bottles. We will assume 5 gallons. The two most comon sizes of bottles is 12 oz and 22 oz.
If you use 12 oz, you will need approximately 48 bottles, and for 22 oz, approximately 30. However, it is highly advised to have several more available because a batch is rarely exactly 5 gallons, and each bottle might have a different amount in it.
When I was bottling, I used between 50 to 56 small bottles.
The first step in using your bottles is to make sure all are debris has been cleaned from the inside, then sanitize. It is not necessary to dry them.
Use any cleaning and sanitizing products you want. PBW, Straight A, Star San, iodine, or others. Mix each with water in separate buckets or tubs.
If any bottles have stuck on gunk inside, you will either need to use a bottle brush to remove it, or soak it for several hours.
At a minimum, dunk each bottle in cleaning water and let it remain for a few minutes, using the brush if necessary to scrub it, pour out the water, then dunk it in sanitizing solution for about 1 minute, and pour it out.
Change the water in both tubs if cloudy or dirty.
The beer should be either in the bottling bucket or fermenter, ready to be put in bottles.
Add 3/4 cup of corn sugar to the beer and mix very thoroughly. This will cause the bottles to slowly carbonate over the period of a week or two.
With a bottling bucket that has a spigot, or a racking cane, fill each bottle, leaving about 1 inch of head. DO NOT FILLING TO TOP! This will cause too much pressure build up and possibly an explosion.
Have the bottle capper and caps available. Soak all caps in sanitizing solution until ready for use.
After filling each bottle, put a cap on it and clamp it down with the capper.
Once all bottles have been filled, place them somewhere dark, whether in a room, closet, box, or throw a towel over them. They should remain away from sunlight which can damage the beer.
Bottles must remain at room temperature! Do not refrigerate! If you do, the yeast will not eat the sugars and create carbonation.
Give the bottles at least 1 week to carbonate, although 2 weeks is better. As the beer ages, the flavor will improve. Some beers will taste fine after 2 weeks, others need a month or longer.
As each week progresses, open a bottle and see if the flavor is improving.
Refrigerate all bottles and drink when ready.