Congratulations on finishing Progressive Improvising Guitar! By now you should be sounding good and getting a lot out of your improvising. To help you practice everything you have learned, there are some extra tracks for you to jam along with.
Try out any of the licks in the book with these progressions and make a habit of improvising your own licks and solos. Above all, keep playing, keep practicing and keep improvising. If you would like to learn more about lead guitar, see Progressive Complete Learn to Play Lead Guitar Manual .