As far as the coins, I would first find out what he CAN do. Can he count pennies by themselves? Then start with just nickels and pennies. Add in a few dimes once he can do this.Slowly add in the rest. Also, I would use real coins if possible. Many kids need hands on before they can do it abstractly in a workbook. As far as the clock, can  he read a real clock? Again, many kids need to practice on a real clock first. One of the skills kids need to tell time is counting by fives. You can work on this anywhere. Also, putting 5, 10, etc. next to the numbers on the clocks in your home would probably help. I do have more suggestions, so write back if you need more help. Good luck!:)

There are some websites that provide kids with a ton of practice and feedback with these skills.  Look here for a list of sites that provide kids with money practice.  "Counting Money" and "The Value of Coins" are 2 of the sites most appropriate to 2nd graders:

http://learningreviews.com/jreviews/Mathematics-Categories/Education/Math/Money-a-Finances_c24_m54.html

For telling time using an analog clock, here's a list of sites where he can practice:

http://learningreviews.com/jreviews/Mathematics-Categories/Education/Math/Time_c47_m54.html

Some kids learn best by using their hands to manipulate items, like the coins or a clock.  Try using these "manipulatives" with the problems on the websites to help him to understand counting money and telling time.