I think Wirth's compiler book is more approachable for a beginner. Once you are done with that book you can also read "Project Oberon" from the same author. This way you can understand the implementation of a full graphical OS written from scratch for a custom made RISC processor implemented on a FPGA. The book and source code are available at: http://www-oldurls.inf.ethz.ch/personal/wirth/ProjectOberon/