Where can I find magazines posted online?

Have you tried just googling the magazine you want to see?

@judochop
Yes but havering no luck yet.

Any new magazine is probably only available through its official website, or subscription service like Zinio. http://www.zinio.com/

Google books has lot of older magazines (and millions of books).
http://books.google.com/

@tripe
I only read two magazines online and I just checked, neither of them provide a pdf format. Good luck.

Here’s subscription information. You could call the library of the closest University and ask if they have it.