I hope no one thinks of my post as bragging or disagreeing with some of the great advice already posted in this thread, that is certainly not my intent. I just thought the readers might get something out of hearing from one example of a high school player that bypassed going to school to sign a professional contract. (Sorry in advance for the long post…it’s rather difficult to share thoughts on such a complex subject in just a paragraph or two…)
Our son signed out of high school and as parents we were very concerned about his decision to pass on a great college opportunity (I could write a book on this subject) and how he would transition to living on his own. He was one of the fortunate few that signed for enough that he wasn’t going to have to try to only live off his meager milb salary. While the bonus certainly helped, he has proven to be pretty frugal with his money and still shares an apartment with 3 to 5 roommates every season (and all the drama that can go with roommates). He also relies on a good part of his food to come from the clubhouse spread, mostly because it’s part of his clubhouse dues and he really hates to spend money on going out to eat. In fact we were quite impressed with his new found cooking skills when he came home in the off season (he makes a mean shrimp scampi)
. When it comes to the game itself, words can’t do justice to the amount of pressure but upon a player to prove his worth every inning, every game and every season… each year it’s all about getting a roster spot at the next level. I will say that as a high school player the organization can be a little more patient on the development side vs. those coming out of college that is perceived to be more “game ready”. Maybe he has been lucky in his transition into “the life” however so far things haven’t been too difficult for him to deal with, staying off the injury list…now that’s another matter. 
Even if you take the money out of the equation I still believe many of the players drafted out of high school these days might be better prepared for life on the road than we may think. Just look at how much travel most of these players are doing over their high school summer/fall seasons. If your son is playing at a level to be considered a draft prospect then there is a good chance that he has logged many miles in a car/bus/plane and has spent many nights on the road during his sophomore and junior summer seasons (Impact Games, PG Nationals, Marietta, Jupiter, AC, East Coast Pro, Aflac, etc...). I know that my son had to make a few of those trips without Mom or Dad to take care of him. Sure there was a coach or other parent that was taking on the responsibility to watch out for him however most of the time he was rooming with another player. By the time he was out of high school he thought nothing of leaving home and taking care of himself. Was it's scary for us as parents…you bet, however I do believe that fending for himself was the least of his worries and he was ready to go when the time came. Is milb a tough, cutthroat business…absolutely? Pro ball is certainly not something that everyone is ready for out of high school but for our player at least it wasn’t something that he was afraid of. I don’t think anyone is totally ready to go from mom’s home cooking and laundry service to doing it on his own overnight however in our experience we found that our son wasn’t thrown to the wolves immediately. His first experience was seeing "complex" ball and dorm living.
One of the things TPM mention for high school players coming into professional ball is spending a lot of their early time at a baseball complex. I agree this can be a tedious thing for the player however from a parent’s point of view we actually saw it as a bit of a blessing sending off our 18 year old man-child to his first job. We especially liked that he had an 11:00 curfew.
While he probably wouldn’t admit it I think he also saw an upside to complex life as well. He signed at the deadline so it was too late to play however he did spend a month at the end of the season working out and observing the GCL and he then came back to the complex for Fall Instructional league. This gave him a chance to get his feet wet in a a controlled environment and it also gave him a good idea of what things would be like when he started his first season. This is getting long so I’m going to close here however it is probably pretty obvious there are many things for you and your sons to consider when making such an important decision. Thankfully he/we had some very smart people advising us along the way so we pretty much went into pro ball with a good sense of what to expect. Many of those advisors were part of the HSBBW family (and this thread), I hope all of your sons have the good fortune to have these types of choices to make in the future. If I can pay it forward and help in any way…you know where to find me.