Usually, most women go to the beautician several times per year. How you generally get it cut will depend on the amount of money you want to spend and how you want it styled. Also, you will find that most women will get their hair cut when the hair grows out of the style... the time varies depending on the length of the hair and style.
How often you get your hair cut also depends on the length of your hair. Shorter hair will need to be trimmed up within 4 weeks, otherwise it starts to look overgrown. Medium hair entitles you to make a visit every 5 to 6 weeks for the most part, it doesn't demand as much attention as short hair. If you have long hair you should go every 6 to 7 weeks, mainly because you will most likely want your ends trimmed so you don't get a split end problem.
These are just averages. Depending on the health and length of your hair you'll you'll probably have fewer visits to the hair salon. It also depends if you have any special occasions or engagement, that's usually another reason women will get their hair styled.
The beauty with hair extensions, is that it doesn't grow. There is no need to visit the stylist unless you need it styled. A perm will endure for one to three months, occasionally they are know to hold their cutrls for a year.
These are pretty basic facts that most of you already know I'm sure, just wanted to put it out there for people that don't:)