If you had a fairy godmother when you started riding...

[north woods gal]

On all the jobs I've worked, I've had to dress business professional, so I had to always bring a change of clothes and all the toiletries I need with me. I used a bike with large rear panniers to carry it all. Pretty tough to stuff a dress or skirt/blouse in a small pack and expect to look presentable. Had no locker, but my boss always let me store stuff in a safe place, so having a good boss is like gold.

One little tip is to also carry a pair of gloves when you ride, just in case your chain slips off the chainrings or have to lift it to pull a wheel. Coming to work with greasy dirty hands does not make a good impression.

One last thing. If you live in a area with a lot of bike theft, beg, plead or whatever to get permission to store your bike inside the building, rather than out in the lot with the cars. If that's a no go, investigate getting a low end bike just for commuting. I lived and commuted in Chicago (bike theft capitol of the world). Most bike commuters I knew used low end bikes for commuting for that very reason. My boss was a good guy, though, and allowed me to store my bike, indoors.