Yourcta.com is home to Chicago Transit Authority.
For those who are not familiar with it, first a brief introduction. The Chicago Transit Authority is an independent governmental agency created by state legislation. It operates the nation’s largest public transportation system and covers the City of Chicago and 40 surroundings suburbs. Enter in the about us section; said section will educate you on their story, vital statistics, how to get around on the CTA, and much more. For those who usually use CTA as their usual means of transport to get to work, study, etc, many online services are offered at this site. For instance, check out the Chicago Card Plus, available to buy online, which allows you to spend less time paying fares and more time enjoying your destinations. Systems maps, trains and bus schedules are available as well. If you are new to this site, you might be interested in creating your own account, so you can have full access to all the services they provide. Visit the website for further information on this. 
