Unless you're a top-pro-prospect already in a Major League organization, chances are pretty slim that you'd be able to play in a Dominican, Puerto Rican, Mexican or Venezualan league -- where the pro winter leagues are. Most foreign winter teams are allowed to have only a few American ball players on a team at a time. And because those slots are filled with top-pro-prospects from Major League organizations (usually set up by agents or minor league player development directors), it's hard, if not almost impossible to get on a team there.
In the summer, however, there are a lot of possibilities to play pro ball abroad, if that interests you. There are pro teams in Europe, for example, that are par with college baseball teams here in the states. The pay is $900-$1,200 a month EURO and you'll only get paid during the five-month season, but you can have your pick of Germany, Italy, Denmark and Spain for places to play.
Now I'm not trying to deter you from playing ball in the winter, but the leagues you may be thinking about are pretty tough to get into -- even for pro players -- without the help of an agent or Major League organization.