I'm not sure what kind of introduction to make, I've been casually engaging in chastity play with my girlfriend for about two years now, thinking of maybe taking it further so I'm perusing the interwebs for info I might find useful.
The first rule of chastity is that there are no rules, do what makes you and your girlfriend/keyholder happy. You do need to have open and honest communication. You may want to discuss with her the benefits of chastity in a relationship. If you need fodder, plenty of threads here discuss chastity in vanilla relationship.