Nice notes on QFT up to Strings:

Quantum Field Theory to Strings Mirkovic (links to more)
http://www.math.umass.edu/~mirkovic/QFT/QFT/qft.IvansNotes.pdf
Quantum Field Theory program at IAS: Spring Term
<http://www.math.ias.edu/QFT/spring/index.html> Hoker and Witten
Quantum Field Theory program at IAS: Fall Term
<http://www.math.ias.edu/QFT/fall/index.html>

Segal's "Fields" book (csome 800 pages online) is referenced too:
http://insti.physics.sunysb.edu/˜siegel/plan.html (also on ArXiv)

KITP Program: Mathematical Structures in String Theory
<http://online.kitp.ucsb.edu/online/strings05/>
(mostly too specialized or advanced for me now)

IntroductoryLecturesonQuantumFieldTheory0510040
These notes are referenced positively on several
other sites and are at ArXiv.org (search 0510040)
by Luis Alvarez-Gaume and Miguel A. Vazquez-Mozo

--
Herb