TITLE: About Simon Donaldson's book on four dimensional manifold
QUESTION [10 upvotes]: Recently I'm reading Donaldson's Geometry of four manifolds. It seems to me that the book requires a lot for background. Additionally, the proof in the book is too sketchy without too much detail. I had a really hard time to digest the content in the book. Do we have other textbook demonstrating the same topic with more detail and background?

REPLY [11 votes]: It's been a while but I remember that I found John Morgan's "An introduction to gauge theory" quite helpful when I was first trying to read about 4-manifolds and gauge theory. While it doesn't go nearly as far as Donaldson-Kronheimer, it does give a gentle introduction to gauge theory. Here's the complete reference:
Morgan, John W., An introduction to gauge theory, Friedman, Robert (ed.) et al., Gauge theory and the topology of four-manifolds. Lectures of the graduate summer school. Providence, RI: American Mathematical Society. IAS/Park City Math. Ser. 4, 53-143 (1998). ZBL0911.57024.