Could be helpful to hear ii-V-I examples?
Here's a linkHere's a link that will play you a random Major ii-V-I.
Here's notation for a specific Major ii-V-I harvested from that link:if EMBED tags were allowed I would have included a player for the music http://www.songtrellis.com/excerptstor/tunetextpool/StackEx1/StackEx1Ex.11110513020039.jpgif EMBED tags were allowed I would have included a player for the music http://www.songtrellis.com/excerptstor/tunetextpool/StackEx%20example1/StackExexample1110513020926.jpg
This oneThis one will play a random minor ii-V-I
Here's notation for one of the minor ii-V-i's generated by the previous link: harvested from previous link http://www.songtrellis.com/excerptstor/tunetextpool/StackExexample2/StackExexample2E110513015730.jpg
Every time you refresh those pages that launch, a different ii-V-I should play for you. The type of the goal chord will also vary, so that you can hear what happens when different members of the major and minor chord families are the goal of the sequence.
I have a largish reply nearly ready which explains why you're unlikely to hear a ii-V-I sequence in a blues unless you listen to jazz musicians who take harmonic liberties with the form.