General guide for Grading your Wacky Packages

Unfortunately if your cards are borderless or have writing on them (front or back), that will devalue them dramatically, at least by 95% or more, most borderless or written-on wackys are worthless, you might as well keep them for sentimental value.
Condition matters a lot in this hobby, cards must be fairly clean, no tears, no wrinkling, not horribly miscut, etc, otherwise the value decreases quickly. High grade cards with only the slightest flaws are called "near mint" (NM) (truly "mint" cards which are flawless are extremely uncommon from the early series). The next grade down is "excellent" (Ex). The next grade down from Ex is "very good" (VG). Middle ground is covered by VG+/- EX+/- and NM+/-.
Since grading can be very subjective, it's always best to try to grade conservatively, and when describing your cards, be as specific as possible, don't just use the terms NM, EX, and VG, but describe all specific flaws so your buyer knows exactly what they are getting, this will make your life much easier when you sell because keep in mind that collectors are generally very picky about condition.
A picture is worth a thousand words. So the following links have some illustrations of grading issues:
Issues related to grading die-cuts