I don't know if this is applicable anymore, but all the formal traininig in the world will not prepare you for what you can only learn hands on. There may be something to formal training - I don't know, I never went through it. I did attend Bible School, majored in Theology and minored in Music (as my aspirations then were in a different direction than they are now). I took one or two mission classes merely for the "easy A" I could get. I never did any missionary training and if I've missed out on anything I am not aware of it.
I read a great book by Myron Loss called "Culture Shock" and it has become my missionary "handbook". It was a great preparation tool for me in anticipating what I would face. Since being here I have read it several times to remind myself that I am not "going nuts"!! haha!
You will face unbelievable shock and a whole gammut of emotions that range from frustration and anger to joy and wonder. Each emotion carries with it a valuable lesson to be learned.
I have been here in Croatia for 5 years now, am fluent in the language, married to a local, fully emersed in the culture, and can't imagine my life any different now. Getting here has been a long and arduous journey fraught with every kind emotion and lesson in life that can be imagined. You will be humbled beyond what can be imagined, tried in the "furnace", squeezed and prodded by the faithful hand of God, and in the end you will be more like Him than you ever imagined.
Missionary work is one of the most wonderous ways God gets deep in the heart and soul of a person to reveal the deep and hidden things of the heart - because as you try to speak a language so foreign to your own and realize that a 4 year old has a greater vocabulary than you it is incredibly humbling. As you begin missing the convenience of American things like dryers and all the little gadgets you find in "Bed, Bath and Beyond" that make life easier you sometimes find yourself growing resentful (or at least I did

). As you grow tired from listening to a foreign language 24/7 you tend to grow impatient. And the list goes on...
...but lest you think that it is all frustration - it's not. It's wonderful.
There will come a day when you realize that you have begun to accept and even appreciate the inconveniences of the new culture. I have found that I prefer line-dried and stiff clothes. Stiff=clean.

Stiff towels are great exfoliaters. Who knew!! I prefer public transport over driving, gas is too expensive, traffic is horrendous, and taking the bus or tram gives me GREAT reading time. I devour books like candy. There are so many positive sides to the negative.
Its a journey - it's not easy, don't let anyone try to convince you that it is. But, it's rewarding - not only in your life but in the lives of those around you. Don't let the difficulties discourage you - because life is difficult no matter where you live!!