A large number of university's that are recruiting student-athletes will ask them to come on an official visit. If you are invited by a coach to come on an official visit, this usually means that the university is very interested in recruiting you.
An official visit means that the coach will have determined your academic eligability, as well as your athletic ability. The NCAA have set rules on visits which differ depending on NCAA classification.
Division I - You are permitted five official visits to any school of your choice. Official visits can begin at the start of your final year in secondary school. Trips are paid for by the university and include accomodation, food, and in some cases tranportation within the country. The only thing you will need to pay for is airfare. The time limit for official visits is 48 hours. Visits should be selected carefully, ensure that you're have a genuine interest in the school otherwise you will be wasting a visit. Coaches are also allowed to be present, but their expenses will not be covered.
Unofficial visits are allowed and you can take as many of these as you like but it will be out of your own pocket. Again, if the school is one that you are not particularly interested in, make sure you save your official visits for ones that you are.
* Official visits cannot go ahead unless the college has recieved both, grade reports from your school, and a score from the SAT exam.
A big mistake I have seen from a number of UK Athletes is there choice not to visit the university. I cannot stress how important it is to see and experience the place where you might be living for the next 4 years! In many cases, students have accepted an offer, turned up at the university and realised that; it's in the middle of no where, it's too big or too small, they don't get on with the coach, they don't like the way of life. It's like purchasing car, would buy without viewing or test driving it? No, you wouldn't, so why do the same with a university? It is essential that you visit and meet the coach and your teammates. Believe me, you will get a great feeling as to whether this place is for you or not.