I dont see why that wouldn't be a bad idea, if I was to hear good things about a book that was out for mIRC, i'd go and buy it, but theres tons of tutorials on websites dealing with mIRC, just out of memory 2 came to mind.
http://mirc.net (mirc.net seems to be down, maybe check back later, (4:53am central standard time))
http://mircscripts.org And always, a mIRC scripters #1 source for help is generally the help file.