1. Divide and Conquer: Pledge or Promise?
First, it's good to know whether your pledges are better tracked through FundRaiser's Pledge Module (optional in Select, included in Professional) or not. That will depend on the make-up of the pledge itself. If a person (or organization) promises to give you a particular gift in the future, and will be giving it to you in one payment, then you don't need to use the Pledge Module, necessarily. The determining factor, in this case, might be whether you need to track promised payments as "accounts receivable" for accounting purposes. If so, you'll probably want to use the Pledge Module, as it makes it easier to do. If not, then you may just need to use the Gift Type Code "Later - Promise to Pay", to record a pledged amount.
If you set payment deadlines, as in Kim Klein's example (see her blog entry here), then you may want to set the Gift Date as the promised date (rather than the date the pledge was made), so that you'll later be able to Group together anyone with a gift/pledge due during a particular time period. Another reason to use the Pledge Module would be for pledges that adhere to the usual FundRaiser definition of a pledge: A promise to pay a certain amount of money in increments over a given period of time. This complicates things by necessitating a payment schedule, recording of individual payments, keeping track of balance due, etc., which the Pledge Module is designed to do.