Besser Associates offers courses that either focus exclusively on RF PCB design or include discussions of design techniques along with other topics (such as EMC/EMI troubleshooting).
New! You can now sign up for Rick Fornes' RF and High Speed PCB and EMI Design Fundamentals course (classroom video recording) right here on RFMentor Academy. Use your existing RFMentor account to purchase one part at a time (8 parts total) for the same price as taking the whole course at once! Each part is approximately 1 to 1.5 hours long and you will receive 60 days access.
Note: the course must be taken sequentially, each part may reference material from the other parts.