M.R.
How old is your kid? And, how many of these 'select teams' are available in your area? Those would be the top two questions that need to be answered before proceeding.
Granted, it was nearly 25 years ago but I participated in travel/select soccer starting at the age of 10. It was a fantastic experience. If my children showed promise and interest in a sport, I would definitely encourage their participation. There are definitely some cons that you may wish to consider:
-If the area is 'oversaturated' with select teams then the concept of a select team is really meaningless. Now, I'm not trying to establish some sort of preferred hierarchy but let's be honest. Not every kid who plays soccer is *that good* that they should be on a select team. If there are several options in your community then the teams get watered down, anyone can play, anyone can coach, and it isn't an advanced level of competition. Later on as a high school coach, we would see this as problematic because every kid who was a part of the select programs (and there were so many of them that every kid was considered 'advanced') thought they were entitled and good enough to make the team. Um, not so much...too many select teams basically means 'Traveling AYSO' where anyone and everyone gets a spot. I'm not for shutting kids out of participating in group activities BUT if a program is a select program then it needs to be just that - 'select' or the top kids - in order to maintain its credibility.
-Check the coach's certifications. For soccer, I believe the preferred licensing body is the USSF (United States Soccer Federation). While the certification is not an end-all, be-all, it does allow you to get an idea of the training the coach has taken. More information can be found by Googling "ussf licensing".
-At younger ages, and this is just my philosophical belief, kids should not be forced to 'specialize' in only one sport. I think if a child shows promise and has passion for soccer and wants to do the select program, that's awesome BUT specializing in one sport (unless they've got like Tiger Woods-like potential) is not the best thing for younger children or athletes. Cross-training, participating in other sports, and making sure to take time off to rest/recover is essential in helping the young athlete to have a more well-rounded physical and emotional contribution to their preferred sport. Additionally, over-participation (for some kids) in one sport can lead to burn out and injury at an early age.
Good luck to you and your daughter - participating with a travel/select team can be a very exciting and rewarding activity that she will remember and cherish for years and years to come! Do your homework and research and if the opportunity sounds like a good one then I definitely say "Go for it!". Above all, just remember to keep this fun and worthwhile for her.