One of the menu options under the Contact Overview menu that is accessible when within a contact record is the Know Your Client section of the contact record:
After clicking Know Your Client, you'll then see the Know Your Client area for the contact and can begin filling in your applicable information for them.
Here, let's look at the Client Review section of this page:
If no data has been entered here, it will be blank as above. To add data, just click the Edit button in the top right corner of this section. You'll then see the below:
Just manually enter your first planned Review Date and choose a Review Frequency from those available in the menu (Review Frequency will trigger Client Review Reminders on your Dashboard):
In this example, August 25, 2012 has been entered as the first planned review date with a Review Frequency of Twice a Year. After entering, just click Save Client Review. It would then look like the below within this contact's record:
As mentioned above, this will trigger a Client Review Reminder on your Dashboard based upon how many days in advance you've indicated you want these to display from the Reminders section of your Site Preferences. Also, you have the option on your main Calendar to display client reviews on the dates they are scheduled (this option is in the Actions box on your main Calendar page).
After the date has passed, the Next Review Date field will update automatically, based upon the Review Frequency you've entered here.