The main and most famous period of piracy, as most people think of it were between 1716 and 1725.
As for the clothing . . .
It it to make for you to wear or for figurines?
A very, very basic summary:
WAISTCOAT
SHOES- most sailors were barefoot aboard ship or wore buckled shoes
SHIRT- linen shirt is perfect. The basic style lasted quite a long time
HAT- tricorns are the "baseball cap" of the era, also sailors are depicted wearing knit caps looking like a "ski-cap" and also cloth wrapped around the
COAT ( I really need some names of coats pirates wore, Its really hard to get any good images i've only looked at frock coats so far and gotten 2 images )
BREECHES- look for info on here about "slops" and "open knee breeches"
- also, sailors were known and depicted wearing trousers. Look at the plates on Anne Bonny, Mary Reede, and Blackbeard in Johnson's General History of Pirates (or whatever the correct title is- I've had a long day)
BELT/BELT BUCKLES- thin belts are more common than really wide ones, buckles were simple and often a full oval shape-> with a "D" or "square" on either side of the central bar)
BALDRIC- look at the pictures in Johnson.
For what you are after, I can't recommend Greg's site enough:
http://www.gentlemenoffortune.com/basic_kit.htm