Recruiting timeline and job skills needed

Most companies for OCR seem to be looking for tech related functions, even at banks or consulting firms. I was looking at Goldman Sachs and Morgan Stanley summer analyst descriptions, and they require computer programming skills for a finance/business internship. I was wondering what kind of computer skills are necessary for those internships? And if they ask IT-related questions at interviews..?

I am also wondering as to when exactly the SA recruiting time frame would be. Beginning of the school year in the fall, or more towards spring? Lastly, what are some ways you could obtain a SA position without going through OCR? (Not that I am not going to take advantage of on-campus recruiting, but if things don't work out, etc)

Thanks in advance, and please share personal experience/advice on this whole internship search deal, as I am quite new and not experienced at all (as you can see.)