2. How to interview well - Interviewing well is a skill that is best honed with practice and preparation. Preparation involves doing your homework on the company and your interviewer, if you know who will be interviewing you. Know what the company does, who major partners or clients are and key information about the company such as industry. Practice comes in the form of actual interviews for jobs, internships, fellowships and so on or mock interviewing with professors, peers or parents.
3. How to behave at social events and network - Social events such as cocktail parties and the like are events that require specific behaviors and etiquette that is learned. Everyone I've ever talked with has either been taught proper etiquette or figured it out on their own through practice. Networking, something I've always said is important, is never discussed in terms of how to in the classroom. It doesn't matter what major you are, the only way you hear about networking tips is if a professor is asked specifically.
4. How to dress at offices - Office dress codes vary massively depending upon industry and office culture. For instance, most advertising agencies allow for business casual (jeans without rips, tears and holes, sundresses, and strappy sandals) while most financial firms require full business dress (suits, high heels and so on). I've never come across a class that actually teaches students to ask about office culture and dress code. You're allowed to do this when beginning at a new company. I would always suggest, unless otherwise told, to wear full business dress for an interview.