Each of these websites is composed of user generated content from people like you. Of the three, Wikipedia is the most popular and best known of the three sites. So what can you do to help make the sites better?
Everyone knows about Wikipedia and a huge number of people use it as a research tool but the number of people editing Wikipedia articles is actually decreasing. Wikipedia is also suffering from editing wars and out and out vandalism. So what can do to help keep Wikipedia a great resourse?
Editing an article for content might feel intimidating, but a lot of the editing work that goes undone isn't content but grammar and cleaning up dead links. While you might not feel that you are qualified to edit an article on quantum physics, you could edit your hometown', county, or school's entry. Once you get the hang of editing, you can even create entries from scratch for parks or local events. I would avoid anything that is opinion based and pages on famous people or political figures. Many of those pages have been locked to keep the editing wars to a minimum.
How to edit Wikipedia
Here is a link to the Wikipedia editing tutorial.
The maps on OpenStreetMaps are used by many websites and apps including Apple Maps. Contributing is actually easy. One task that anybody can do is to add information like restaurants, stores, parks, churches, libraries, schools, and government buildings. I do wish that OpenStreetMap would make editing a bit easier. You can also get apps for your smartphone to help you map roads. I do wish that Open Street Map would add walking trails, sidewalks and parks. While Google Maps, Bing Maps, and Nokia Maps are all great resources they are also all controlled by companies. You can not download any of the maps and you can not edit them. OpenStreetMap is open for all to use and to update. This means that local businesses can update their location and opening and closing times as well as add new locations. For small towns it means that every store and restaurant can be added to the map without waiting for Google or Microsoft.
How to edit OpenStreetMap.
Wikitravel is probably the least known of these sites, but it is the also the one you could make the biggest impact on. Who knows more about where you live than you do? You will find many of the entries in Wikitravel are just stubs or lacking in detail. This offers a great opportunity for you to contribute to your local community, as well as the Internet. Another way to help is to use Wikitravel and let other know about the site. The more people that know about Wikitravel, use Wikitravel, and contribute to Wikitravel the better it can get.
Editing Wikitravel.Do not put in things like this is the best bbq or pizza restaurant in town since that is just opinion and is better left to review sites. Do include points of interest and useful information for people traveling.
How to edit WikiTravel
Here is a link to a video tutorial for Wikitravel
I have contributed to each of these websites over the years, I have edited entries on the Wikipedia about the North American A-36, added some businesses to OpenStreetMaps, and edited the the entry on Port St. Lucie Florida on WikiTravel. The idea behind these sites is "many hands make light work" so pitch in and make the Internet a better place.