Create Flyers for Website Marketing

We need 8.5 x 11 tri-fold flyers & single-fold version of the same for multiple websites. We have had other designers working on this but the projects don't end up formatted properly and waste our time. Somebody who knows how to make things fit & show up well on 8.5 x 11 colour laser printed, without any further effort on our side, is what we need. One of the designs is already done and needs to be re-formatted. The others can be created off the websites.