A hair stylist and a barber aren' t that different anymore, with the exception of old fashioned barbers in the poorest area of a town, as barbers have long learned to do razor cuts, layering, blow drying etc. etc. in order to keep their more demanding clientele.
In a hairstylist salon you will first have your hair washed, in a special area, by a junior staff, then the stylist will discuss your hairstyle with you. Obviously it depends on the length of your hair, whether or not you want your hair coloured, want hair extensions or braiding etc.
If you already have short to medium length hair the process will be sweet and simple, the same as if you went to a good barber shop.
Have a look at
http://coolmenshair.com/ go past the shaved head guys and read how the surfer hairstyle is done.. layering by a razor etc.. if this was done to you, you wouldn't really know, except for the stylist using a razor instead of scissors (but they also use these)
more choices of hairstyles in the right hand column.
The longer the hair the more choices you have to style your hair yourself in a different way everyday: free flowing or tied in one pony tail or several or with a short pony tail on top and free flowing hair below.
With short to medium hair, you pretty much keep the same style, unless you like to part your hair in a different place every time you shampoo....
The cut will last as long as a barber cut. Most guys wait 3 weeks to a month. My dad had short hair yet would go every single week...It annoyed barbers or hairstylist, as they couldn't do much to his hair, and after a few months he was told to go someplace else..
I am not a barber or hair stylist but used to have very long hair many moons ago .. I loved it but it was a hassle too..