Do you want to read Indian classics in the original Do you want to progress quickly beyond the basics Do you want to reach a high standard 'Teach Yourself Sanskrit' is not only a primer, but also a work of scholarship, for the book contains much original material on Sanskrit syntax and usage. The carefully graded chapters explain Sanskrit grammar and style with exceptional clarity. The text includes an introduction to the n gar script, a useful explanation of how to use Sanskrit commentaries, plenty of examples from actual Sanskrit works, extensive vocabularies into and out of Sanskrit and a full key to all the exercises. The text has been completely re-set for this 2006 edition.
I am seeing progress with this book, but I have been using this in conjunction with (to a lesser extent) the Maurer Sanskrit textbooks - both have their uses but if you intend to 'learn' Sanskrit in any meaningful sense then I think it is best to use the books in conjunction with a Sanskrit teacher. Others have noted the issues re misprints (there are a lot!) and the poor quality of devanagari - this seems to be exacerbated from chapter six onward, where the script appears to be printed in a smaller size than in prior chapters. This may seem a minor gripe, but for beginners it really does make life rather difficult. I also found that Coulson addressed the cases of address rather haphazardly, doing half a job in the appendices rather than spending sufficient time on them in tbe main body of text; this might be because he assumes knowledge of other Indo-European languages, specifically of Latin. For us younger students, this is an assumption too far (though the book was published in the 70s, I think). Coulson also spends a lot of time talking about grammatical features and paradigms that are largely irrelevant to students like me who are reading Sanskrit in order to study Indian philosophy - not everybody is a grammarian! Overall, the book is helpful and it has proved valuable in my making rapid progress with Sanskrit, but I stress that this progress has come in conjunction with regular meetings with a PhD supervisor fluent in Sanskrit who can address things omitted from the book. Still, it is definitely worth perusal by any budding student of Sanskrit.