While everybody's hair is different hairstylists often recommend that you don't wash your hair every day with shampoo and conditioner. Once your hairdresser gets to know your own particular hair will be able to recommend the frequency of washing.
Asking friends and family for recommendations is often a good start. Have a chat to your intended hairdresser about what you would like done and ask for their recommendations for your hair. Often in this discussion you can get a feel for what they are like and whether you will be comfortable to honestly discuss your hair needs with them.
The costs can vary significantly, this will depend on the particular hairdresser and your requirements. For example, if you have a large volume of hair and are requiring foils as part of your treatment, it's going to take a lot longer than someone who has a bob. You hairdresser should be able to give you some idea of cost before you go in, so discuss it with them before your appointment.
You'll find most salons require an appointment to be booked. There are some that offer walk ins and these salons can often be found shopping centres.
Generally 6-8 weeks is the time frame when most people will get a haircut. If you leave your hair uncut for too long you can get more breakage and splits which end up causing damage to the hair. This often means that more hair will need cutting off in your next appointment.