Recently I came across the new book Quantum Field Theory – Lectures of Sidney Coleman (World Scientific; 2019). This is a transcription of lectures given to graduate students at Harvard in the academic year 1975-76. The lectures were video-taped (the videos are still available on the web, although the quality is very poor).
Sadly, Coleman died in 2007. This book is essentially a transcription of these lectures by several other physicists. Problems given to the students who took the course are included, along with comprehensive solutions.
If you look up this book on Amazon, you may be frightened by the price (£74.38 in the UK; $87.86 in the USA at the time of writing) but don’t be put off. The book is 1152 pages long, has a large format and smallish print, so there’s a lot of material in it, and in my opinion is a bargain at that price.
So far, I’ve read about the first 100 pages, and find Coleman’s exposition to be clear, readable and, at times, humorous. Details of derivations that Coleman skipped in his lectures are often provided in footnotes by the editors. It’s easily the most accessible QFT book I’ve come across so far. The only negative point is the lack of simpler exercises for readers to work out as they go along. The problems that are included tend to be non-trivial, although as I mentioned, complete detailed solutions are provided.
I’d highly recommend this to anyone seriously interested in learning quantum field theory.