The designs do last a lot longer and they look better too. Iron-on transfers tend to peel or crack after a few washings. They have a background and edges, where silk screening leaves you with just a design. My friend runs a business doing silk screening and she built her own equipment. It's a revolving wooden frame with paddles, and she just moves the shirt or tote bag from one paddle to the next for each color. She built her own screens too, from wood and screening. She bought a computerized printer that prints the designs on acetate. The inks can be pretty expensive.
But even 10K is not that big an investment if you are planning to do it for a living.
I've done silk screening on a much smaller scale, you just use cloth mesh and make a different screen for each color. It's fine if you are only going to make a few of something.
You will want to have a copy of Adobe Creative Suite 5 . You should start your training in Adobe Illustrator as this will give you a better advantage when working with color and screen separations for your ready to print designs. Moving on to learn Photoshop next. Don't make the mistake of thinking that the whole design world revolves around Photoshop.
For the actual training, if you are not in school already. Then I would recommend the on-line training videos by http://www.lynda.com . They have some samples of the Lynda videos posted on youtube. After 17 Years in the business I can say that I think that her videos are the best that I have seen. I don't work for them.
I actually work daily designing and Printing in Adobe Illustrator, Indesign and Photoshop files. I have designed for clothing lines and you will find that 90% of your work will be done in Adobe Illustrator.