I highly recommended both books. You must read them. And you must read them in that order as the first sets up the second perfectly.
I always intended on reading the books after I saw some good reviews of ASG. Yesterday I was sick in bed and it was on a recommendation list so I flat-out bought it without even starting with a sample.
The funny thing was the name Tamara Shopsin sounded familiar to me for some other reason, and when I looked up the second book I discovered why: I write in her 5 Year Diary every night before I go to bed.