This very much depends upon your own circumstances and how your sport fits in with your overall academic expectancies. Remember, you are playing your sport to compliment with an academic program and not the other way round. Depending upon your academic record coming out of high school and the level in which you have competed at in your sport, an important step is to start contacting coaches as suitable universities.
If you are looking to be recruited at a local college then obviously contacting the head coach or assistant coaches at the specified school is the best way to get the ball rolling. This will be the same for all student's although if you are looking to be recruited anywhere across the U.S. then start to check out NCAA, NJCAA, NAIA at the member schools for your specified sport. From here, you can start short listing which specific programs to contact. E-mailing a coach is the first step, however make sure you make a template if you are contacting several coaches but personalise that template to the specific individual that you are contacting.
It is also important to put together an athletic CV with all your sporting achievements as well as academic results thus far. Work experience, and any volunteering may also help as a coach is looking for many different aspects in terms of whether your personality and character will fit with the program, therefore this type of thing will not hurt your chances of being recruited.
I think that e-mail is the best initial way to contact a coach and see what his response is from there. Depending on how far you are located from the college, he/she may ask for video footage, therefore make sure you edit relevant footage which highlights specifically you ability within a short clip so that the coach can get an idea of the standard of your play.
Obviously visiting a specified program is the best way as many universities will offer a general "try out" where you can really express your performance and thus better your chances of being accepted onto the program and with scholarship if thats what your looking for.
Lastly, sports agencies like Athletes USA (largest global scholarship agency) have links to thousands of coaches thus give you the best ability to promote your sporting abilities however they do charge a fee but these vary depending upon the certain packages on offer to promote your abilities.