You may be just starting your career, but you can shake hands like a CEO. Extend your hand with confidence, offer a nice firm grip, and let the recruiter "lead." Handshakes that are too delicate or overly robust are a mistake. If for some reason you aren't completely comfortable with the ritual handshake, your job search is going to be stressful. The job interview process has been referred to as "handshake to handshake combat," and you need to be able to carry it off comfortably.
Listen carefully as names are pronounced. Ask for a name to be repeated if necessary. Remembering names is more than a nice social amenity, it's an important business practice. If your name is mispronounced, correct it politely and immediately. You risk embarrassing future colleagues when they find out they've been mispronouncing your name.
In a healthy business climate, men and women assume equal responsibility and are accorded equal respect. Social courtesies (opening doors, helping with coats, etc.) are extended mutually. Flirtatious or sexist behavior is not acceptable and you don't have to humor anyone who thinks it is.
Show courtesy and respect to everyone. In addition to being the right thing to do, your behavior is being observed by employers who will (rightly) assume that you will treat customers and co-workers with a similar degree of civility. Arrogance and sarcasm are equally unattractive.
If you feel at a disadvantage because you lack experience in business/social situations, invest in a good book on etiquette. It will give you confidence.