Sandboxing and Profile Signing for release

I’m trying to build an app for release, possibly on the mac store. One of the requirements and urged suggestions is to sandbox the app whether releasing on the store or not. The Apple recources seem to be geared specifically for objC code and makes use of a lot of NSObjects. Does that mean I need to use a Cocoa Cinder Block? Has anyone successfully sandboxed their cinder project? I have a pretty large app but when I try sandboxing, it just crashes at build. How do I go about sandboxing a “user selected folder”?
Also, what’s with signing the app with my developer profile? Do I need to do something with that to let a friend test my app on their computer or for the public release? Cinder defaulted the profile to ad hoc but I changed it to my Developer profile and it won’t let me set it back. I’m finding that Apple has made releasing an OSX app extremely convoluted in information. I just want to share my app… Thanks in advance.