Both books are good, although both are by idiosychratic authors. I didn't find Frawley's second book as humourous as the first, though that might be a case of over exposure. However Frawley is eminently readable and the book is a good one - Frawley knows what he's talking about.
I've just re-read Lehman's book and she's not as readable as Frawley, (few authors are). At the time of first reading the chapters on historical background were invaluable but now the two volume work by Nick Campion outstrips it easily. At the time she wrote it she was still using the outer planets and seemingly looking for a way of incorporating traditional practices into a modern Astrologer's work. The book at the time was a breath of fresh air and I loved it, second time around I know more and found some discrepencies with actual traditional practice - the chapter on profections is off beam. Nevertheless it's a book which is a very good start for someone coming from a modern Astrology background.
However the horary textbooks of both writers are far better and horary is a good way to get into the nature of traditional Astrology. Frawley's is simply called the Horary Textbook and Lehman's is 'The Martial Art of Horary Astrology (she's into martial arts). The books give two different approaches and they make you think, especially if you end up reading both.
If you wish to read one or the other of the two books we started with, I'd say Lehman, simply to diversify your sources. If you are going to try horary, then either is a good choice. I read Lehman first, simply because Frawley had not then been published. Both are really valuable for a horary Astrologer. Also a fair amount of what Frawley puts in the 'Applied' book is in the Horary Textbook.
If you are looking to keep the budget down Joseph Crane's 'A Practical Guide to Traditional Astrology' published by ARHAT is good. If you want a history but are not prepared to shell out for Campion's set then James Herschel Holden's 'A History of Horoscopic Astrology' gives a good picture of development up to the present day.
