if you don't know how to buy a suit i will show you how to make buying a suit a little easier for yourself to get you started in the right direction at least.
before you even go out looking you should take time to know what you want, you can do this simply by going online or even searching through magazines. this will make it alot less complicated when you go out also maybe try do your body measurements, if you don't have a measuring tape dont worry about it they will usually do it at the store.
after you have a general idea on what you might like its time to head to the store, now when trying on a suit there are a few things that you should pay attention to here are the main keys when buying a suit. try put these things to memory it will help you get use to how a well fitted suit should fit on yourself.
*shoulders - the suits shoulders should hug your own and should not feel baggy or look like they are falling off your shoulders.
* chest- button your suit with ease but there shouldn't be more than a fist worth of space in between your shirt and jacket length.
* length- when your arms fall to your side you should be able to cup your fingers under the sides of your suit jacket.
* pants- should be slim, comfortable yet not baggy and fits naturally on your hips.
these are the main things you should think about when shopping for that new suit so try keep in mind after you know and feel comfortable looking at suits the rest is all style. heres somethings you should consider like how many buttons would you like on your coat there is 3 button 2 button and 1 button. if your not sure on which one to choose the way i usually pick depends on the look your looking for so 3 button is a very conservative old fashioned style 2 buttons is the now modern look if your not sure the 2 button would be the best pick. the 1 button is old school but still very modern.
after finding a suit to your preference take your suit to a tailor to have it altered for a perfect fit.