Commuting Gear
Motorcycle riding gear serves three main purposes: It provides protection from cold and wind, it keeps you dry if it rains, and it can provide additional protection from injury should you crash. A rider using his or her bike to commute to work cannot always choose the weather conditions in which they operate (a sunny morning can turn into a rainy afternoon..) and should keep this in mind when selecting riding gear.
Unless you plan on keeping a selection of work clothes at you place of employment, it probably makes most sense to wear your work clothes under your riding gear. This pretty much rules out leather riding suits. Speaking of leather - I'm not a big fan of riding chaps. They provide no protection whatsoever to your buttocks and thighs should you crash, and they provide only limited rain and cold protection. Also, unless you are walking into a biker bar, people can give you funny looks when you wear them off the bike. Leather is also difficult and expensive to clean, and provides only limited rain protection. A synthetic jacket and pants or full riding suit is the best way to go. All you need is a place at work where you can stash it during the workday.
For general commuter wear it is hard to beat the custom-fit Aerostich "Roadcrafter" suit. Not only does this ballistic-nylon one-piece come with removable (and washable) linings, but it also has removable body-armor in strategic spots. The suit is also pretty much rainproof in all but the most extreme conditions. It is also liberally marked with high-visibility reflective tape, and has more storage pockets than you can shake a stick at. The only downside is the cost - more than $700 the last time I checked. As an alternative, you could get a one- or two-piece suit from other manufacturers - Firstgear, Joe Rocket, Alpinestars, Cortech, etc. - but the quality is not necessarily as good as Aerostich.
As far as footwear - unless your job is one where you can get by wearing boots you will probably have to take street shoes with you. Riding a motorcycle in most street shoes (sneakers, mocassins, wingtips, etc.) is unsafe (they don't provide enough grip to let you keep the bike upright), uncomfortable (they let wind blow up your pant legs), and bad for the shoes (the toe of your left shoe will get scuffed from the shifter peg.) I like the "lineman" style motorcycle boot - it gives good on-bike performance and doesn't look too goofy under street pants.
No matter where you live, you should wear gloves at all times on the bike. The bloodiest bike injury I ever saw was a guy who took a 5 mph spill and scraped most of the skin of his palm and fingers - apparently he still has trouble holding a pen a year after the accident. He also lost about two pints of blood before the EMT's could staunch the flow.
As far as avoiding "helmet hair" - you could try wearing a skullcap or do-rag underneath, but the best bet is to develop a hairstyle that is compatible with wearing one. Alternately, take a comb and a can of hairgoo into the washroom at work to straighten things up before you start your day.