There is still time to get some riding in this week, and test your wings at riding to work!
Here are some quick hits, that might kill some excuses you might be up against....
1) Don't carry more than you need to: Best examples:
Bike lock: don't carry it with you - leave your lock attached to the bike rack -- it will be waiting for you when you arrive the next day.
Shoes: leave a pair of work-friendly shoes in your desk drawers. Change out of your athletic/riding shoes at your desk.
Ladies: hair dryer, hair care items: have a prep-duffel in your desk with these items; when you get to your desk, pop into the restroom with your bag and finish your morning routine. There are outlets on the walls.
Business clothes: there is a dry cleaner on site, and you can bring some hangers and use your cubicle "coat closet" to house dress shirts, skirts, slacks, etc. This is a big help if you are worried about wrinkles. If you pack your items in a bag, ROLL your clothes to avoid fold marks and wrinkles.
Desk supplies: Have things like spray-on wrinkle relaxer, Febreze, lint rollers, deodorant, subtle and clean perfume, etc. in your desk. Never let anyone KNOW that you rode to work, look professional and clean, without carrying a 50 lb. backpack everyday. There is no reason you can't even wear a suit and tie (men), or a sensible business pantsuit (ladies) at work after cycling in - use your resources - you can still look good, and not rumpled or sweaty.
2) Don't go broke on cycling clothes or the bike: T-shirt and shorts are fine. Only if you develop a habit and start to see benefits from the sport-specific items should you buy them. Don't get fooled into riding to work *IN* your work clothes unless you only live a few blocks away, but keep your initial investment low. Same with the bike. A BMX bike will get you there - seriously. You don't have to spend a lot of money to get rolling -- so don't, until such time as you are committed and start to see a benefit by upgrading equipment. Look at garage sales.
3) Be proud of your choice. Walk tall with your head high as you come into the building. You are making a personal choice and proving to others that it CAN be done. The comments about the "fancy bike shorts" and such will pass. Rise above it. This ain't high school. You're doing the right thing, and lucky for us "green" is now "chic". In this time of cultural change in America, you are a pioneer. Smile.
4) YOU DO NOT HAVE TO BE AN ATHLETE TO RIDE TO WORK. I am not an athlete. I have a knack and passion for cycling, and I do it a LOT… but you don't have to be in shape, or a nut, or a psycho to do this. When I first started riding to work, I had no business being on a bicycle. The fitness comes, there is a progression to it - but never think for one second that "I'd die if I tried that", or "I'm lucky if I can survive the walk to the parking lot."
You can do it, because *I* can do it.
Take the first step - the rest comes.