I used the Official 10 LSATS book and I found it really useful for thinking through challenging CRs. I worked on the problems in the appropriate sections despite not having the answers. If you have any doubts on specific questions, you can post them in the forums and I'm sure everyone would be glad to help. However, I'm not sure if we are allowed to post the exact questions anymore... better to check with the admins on that.
I hope my reply gets to you in time... GOOD LUCK!
Jo1to6, what specific LSAT book did you use for CR? Would you recommend official releases of LSAT actual tests? Since Official LSAT does not have answer explanation, will it suffice just to take tests? I'm especially concerned about bold face CRs for which explanations would be a bonus.