If you are starting from seed I would recommend sprouting a bunch initially. Once it's getting tight, remove your weakest one. Then when it's getting crowded again, remove the weakest one, eventually leaving you with the most vigorous out of a hand full of plants. This also gives you some room for error in the begining, if you screw one up you'll have others on deck. I would do this until you get your best ONE or TWO plants.
If your growing from clones you could honestly flower almost as many as you could fit in the space a la 'sea of green' or SOG style. I wouldn't recommend this for a beginer, just wanted to let you know it all depends on how you grow/what you want to do.
I would highly recommend growing only 1 and utilizing some LST(low stress training). Here is a pic of plant that was tied down when it was about 4-5 inches tall. Instead of a taller plant with one main cola with lateral branches that produce popcorn bud, you get one plant that is easier to manage and each budsite will be almost identical. Every branch you see in the pic will be a top cola. 1 plant bent over LST style is your best bet.