I'll second The Art of Unix Programming - despite the title, it has many broad programming and software architecture lessons, and "The Unix Philosophy" is applicable far beyond Unix.
*but be aware that he's a polarizing figure and opinions of his merits differ
(and if you happen to have a differing opinion, please use the reply button instead of the downvote button)
TAoUP is a good book on the Unix Philosophy, but it's worth noting that the ultimate expression of these ideas (Plan 9) was a failure, and the 'everything is a file' metaphor is arguably incorrect. I hope I didn't give the impression that it was not worth reading, especially in the sense that there are few other good sources for that information (even using Unix is not likely to teach you much about its whys and wherefores). I just think that it should be read in the proper context, and that recommendations should try to include that context.
And I'd bet that a lot of programmers wouldn't be working on and with Linux right now if they hadn't have read that book long ago.
Both of them changed my career path from Dos/Windows to Linux