I have some contact to the "Stappenmethode" (step method), since in our club the juniors work with the booklets. You can get a first impression about the difficulty level in the weekly renewed tasks:
http://www.stappenmethode.nl/en/puzzle.phpIn the teachers hand books you'll find the solutions and many informations about how to work with a class of kids. In my opinion the material is not the best for an adult who is working himself btw. it is getting expensive with the trainers books.
The Jussupow books begins nearly where the step method ends.
In your case i would consider to work through
www.russell-enterprises.com/rei-publications/1001-brilliant-ways-to-checkmateand
www.russell-enterprises.com/rei-publications/1001-winning-chess-sacrifices-and-combinationsor any other great collection of tactical problems and then go to the Jussupow books. The idea is to get enough tactical and calculation skills, which is required for Jussupows bootcamp chess books.