When beginning a cardiorespiratory training regimen<its best to plan for what sessions per week?

It depends on the session you have available to you. You can do cardio all but 1 day out of the week. Your body will need a day off. Start with about 30 - 40 mins of various activity. Then, but month 2, you can up it to 45 - 60 mins per session. You can do treadmill, aerobics, running outside, plyometrics, etc., that will count towards your cardio. For more fitness & nutrition tips going through your journey, subscribe to my blog at http://www.jessicajstone.com. Hope this helps!