confused on syncing calendars between iphone 5 and imac

entered new appts on iCal but didn't sync to iphone5 via iCloud because I have OS 10.6.8 which offers "mobileme" not "icloud". So I had to check to sync calendar and remove icloud option on my phone. Am I doing this correctly or am I totally confused? I am not well educated on the use of all of these features and it's quite confusing for me, please be patient.

I would like to be able to enter on any device and have all devices updated. I would also like to have my comcast email in sync, so if I delete messages on one device they are deleted on all others. Is my problem that I don't have icloud on my iMac?