Be aware that all these historic patterns assume that the user can sew and knows something about tailoring to customize a pattern. Getting a good fit requires cutting out a mockup in muslin or other inexpensive fabric and fitting to the person before making the final garment.
Reconstructing History - Historical Sewing Patterns
The Tudor Tailor - patterns and other goods
Haptic Historian Amanda LaPorta - Excellent research into tailoring methods and clothing reconstruction.
The Renaissance Tailor - Facsimile copies of extant tailor's manuals from the 16th and 17th century. Also sells ruffs and collars.
The Couture Courtesan - Samantha McCarty's blog on historical costuming.
Old England Grown New - Facebook page dedicated to exploring 16th and 17th century apparel.