What would be your advice to someone who's about to write a compiler? I'm planning to start by reading the Dragon book.
Lastly, the book's appendix has guidance for writing a compiler for a subset of the C language.
For for it! Start small and increase. But seeing a program in your own language output something makes it all worth it :)
If you plan to buy the book, you will have to go to Lulu.com and search for it, as order links seem to be down after a site redesign.