Here is some guides that you can use when you are stuck, but try to finish the games at your own first because it more fun when you know that you self have made it.
Single Player Demo Guide
This is the complete guide to the Settlers 3 Demo (Singleplayer one). It contains detailed instructions to finish the demo as well as gameplay screenshots to show you how to do the more challenging moves. This guide is also a great place for someone new to the game to start and learn the basics of Settlers. To view it click here.
Single Player Mission Guide
Having trouble with any of the Mission levels of the 3 Races? We have all the help you need to destroy all enemy forces. Click on the race to view the walkthrough for that campaign: Egyptian Campaigns Roman Campaigns