You must be positive, but more important than that, you must make the talent feel involved in the process. Ask questions. Ask why they did certain things that might be negatives. Ask how they feel about their show, individual segments, whatever. Ask what they need in order to improve. Listen genuinely and make note of what they say. You're not obligated to do anything your talent suggests...the important thing is that you make the talent feel as if they are actively participating in decision making. This builds trust between programmer and talent, and adds to the credibility of the programmer. Beware of lectures. Many a programmer have lost legitimacy among talent by taking this route in meetings. Talent (and this is especially true of programmers who have their own air shifts) will start nit-picking your own style in their minds, leading them to discount what you say if you take a hard-line approach.
Personally I listen to the audio prior to the meeting and make a *short* list of notes. I'm talking like, no more than what you could fit on a Post-It note. That's another thing -- avoid sitting down with a notebook (or other large piece of paper) in hand. More than anything, this goes to the talent's mental perception of the meeting. I try to pick three topics and stay on those during the meeting. Any more than that and you are going to be doing yourself harm because it will be an overload for the talent.
I record talent airchecks on my own computer and try to make a 5 to 10 minute composite of recent breaks. This is for a music show, not a talk show (obviously you would need much more content in that instance). For your morning show I would go with bi-weekly or weekly meetings, unless your morning show is comprised of fairly inexperienced talent. Remember that above everybody else, your morning team are the anchors of your station. They are the people who I would want to be the most interactive with in my meetings.
Remember to keep the talent involved and end on a high note, offering an open-door policy regarding any questions or assistance they might need.