I'd second Bob's suggestion: find an area scout, learn from him as an unpaid associate scout. I know several guys who began as unpaid associates and are now paid area scouts. All those guys, however, played (at least briefly) as pro players.
You'll find out pretty quick if you can deal with the working conditions, paper work and details - without spending the money on scout school. After a while, you will meet the other area scouts and leverage their knowledge into your learning (each scout has unique perspective, approach, views and I've found that most will share that selflessly).
Most area scouts don't make that much money (though the mileage reimbursements can be huge) and are either doing it for the love of the job and/or as the beginning rung on the long climb up the scouting chain. The advantage of being an unpaid associate scout is you can pretty much dictate your availability and limits of your time and travel - all the while learning and watching baseball without the pressure of it being a real job.
Like everything else in baseball, the system is designed to weed out those that aren't fully committed - and beyond. Long hours, low pay, bad food, lots of writing and detail work, parents, poor weather, political fighting within the organization, and more, are the job conditions. During the season, scouts will often work seven days a week, arriving at game one for bp at 1:00 and ending the day at game three 100 miles away at 11:00. Then head home to write up players, upload film, brief the bosses (email or phone) and sleep (not necessarily in that order), before doing the same thing the next day. Hard, hard job.