"how long is training?"
From the day I started Indoc until the day I took my checkride was 1 day under a month. Most airlines take at least a month and a half to do the sam e amount of material. You will do 10 days of Indoc, 7-8 days of systems, about 4 days of sim, and 4-5 days of flight training (yes, you will do V1 cuts and single-engine approaches IN THE AIRPLANE). After that, you will have about a 4-5 day trip to complete your IOE.
"what can I do to prepare for it and what is the cause for the wash-out rate?"
When you accept a class date, a packet of system limitations and emergency memory procedures will be mailed to you. Memorize it completely and verbatim. Also, make sure your instrument skills are sharp. Take a 172 up and fly a full NDB approach, a circle, an arc to a VOR, and a hold, and fly them back to back to back at 100 kias, keeping in mind that you will be doing them at 160 kias in the Beech. The sim is very sensitive, and it will be glaringly obvious if your scan sucks.
I would say that the biggest reasons for the washouts are:
1) Lack of experience and maturity among new hire candidates. This is the first airline job for almost all of the new hires, and there is a ton of material that they have never seen or heard before.
2) The shear volume of material covered in a minimal amount of time. This is the definition of firehose training. Like I said earlier...what most airlines cover in 6-8 weeks, we cover in 4. A typical daily schedule in training looks like this:
0700: wake up (earlier if you need to do some last minute studying)
0800: class starts
1200-1300: lunch
1700: class ends
1730-1800: dinner
1800-0000: study non-stop
You will probably only get a total of about 3 days off during the entire training period, and, if you aren't from the Denver/Cheyenne area, you won't be able to go home during training.
3) The company wants to see you sweat a little bit, so they put some pressure on you. The interview was just the beginning, you need to prove yourself in training. They have very little invested (financially) in you up to that point, and if you can't cut it during training, you definitely won't be able to cut it on the line, so they are willing to cut their losses if need be. Remember, your hire date is your checkride date, so you aren't even an employee during training. This makes it very easy for the company to cut bait. It's not very difficult to find another pilot to replace you that can start next month.
"what is a typical schedule like...do you do 4 on 3 off or something like that?"
That would be really nice if it was. You get 10 days a month off guaranteed...and that's all that's guaranteed. Oh yeah, and if they need you, they can junior man you on your days off.