Team beginners should use these problems for general practice. They should at least glance at the solution at the very back even if they get the answer correct. There are frequently multiple ways to do these problems. The more approaches you are familiar with, the more problems you will be able to solve.
There are 18 sheets of "Warm-Up" problems (easier) and 9 sheets of "Work-Out" problems (more complex). As soon as you get the hang of the warm-ups, start mixing in work-out sheets. Each type of sheet gets harder as you work through the book. There are also 4 sheets of "Stretches", each in a single subject area. These have the highest level of difficulty. Feel free to skip if they are too hard.