Can anyone help me find out how many Sonatas that Telemann wrote for the flute, and maybe where he composed each one?

I tried the Grove Music Encyclopedia, but I can't find any info specific to the flute.

"Georg Philipp Telemann has the dubious distinction of being included in the Guinness Book of Records as the most prolific composer of all time. He composed twelve complete sets of services (one cantata every Sunday) for a year, 78 services for special occasions, 40 operas, 600-700 orchestral suites, 44 passions, along with numerous concerti, sonatas and chamber music for various instrumental combinations. In his time, (he was a contemporary of J.S. Bach), he was regarded as Germany’s leading composer." from:
http://www.fuguemasters.com/telemann.html
Some geographical info there.

I really think that he wrote more than 12 Sonatas for flute. I know of the 6 Method Sonatas right off the top of my head and if you include the Duet Sonatas for 2 flutes (Op2 and op 5) that's 18 for starters not including the ne bok of 4 Sonatas that includes the common one in F major. I believe that if you dig deep enough, he was writing Sonatas for a Periodical (magazine) and the flute was very popular at the time. THe other issue is that he wrote for violin and Recorder(Blokflöte) and with very little adjustments, these pieces can be and were played on the Flute.

~Bilbo
N.E. Ohio

Also if you can't find anything in Grove's Dictionary of Music and Musicians and you have a decent library, try "Flute Music of the 18th Cnetury by Frans Vester.
~Bilbo
N.E. Ohio

Did Telemann ever do anything besides write music, like collect stamps or anything?

Well there's actually two sets of 12 Fantasias AndrewB. The second set is more idiomatic of the Violin because of the type of writing and/or for Recorder(Blokflöte) because of the range being higher but are playable on the Flöte.

Erin,
Telemann was a fairly well respected Church Music director in Germany. He once beat J.S. Bach out of a job. He was so much respected that Bach's sons seemed to follow his more newer music writing style over J.S. Bachs. This led to Style Gallant/Rococco music(uggh) and eventually the Classical period. Telemann was C.P.E. Bach's god father so from that fact you could assume that the two famlies were somewhat close.

~Bilbo
N.E. Ohio