Cycling to work, especially during the summer months, can be a moist and humid affair if you do it wrong. However, I've honed it to a fine art, ensuring that no matter whether my employer has showering facilities or not, I ( or more importantly, my colleagues) have not had to endure the horror of a pungent day in the office.

• Give yourself cool-down time - If you've got showers in work, great. But you can still end up a sweaty mess if you get it wrong. Give yourself plenty of time to get showered and make sure you've cooled down and have stopped sweating before you get in. You'll only sweat more once you've left the shower.
• Start your journey clean - If no showers are available at work, you're on damage limitation. Have a shower in the morning before your commute. That way, at least it'll be clean sweat.
• Take it easy - If you can change clothes at work/haven't got time/can't be bother/don't need to, just take it really easy on your commute, enjoy the sights and sounds, drop a few mph. On a short commute, riding at 12 mph rather than 15mph won't make a huge difference to your journey time, but it'll probably halve the amount of effort you need to put in.
• Base Layer Lore - Wear a non-smelly base layer. I use merino wool, which just plain refuses to smell even after multi day cycling trips. If you don't need to be 'office-neat' in work you can leave it on all day under your clothes.
• Keep a 'cleaning kit' at work - deodorant, hairbrush, hair products, towel, shower gel or baby wipes (depending on facilities)
• Rainy day commutes - especially in the summer, can be really difficult, especially if you can't get changed at work. My advice is find the most breathable, lightweight waterproofs you can and take in really easy on the commute itself. A change of socks and footwear at the other end should be all you need. If you need to be 'office-neat' bring your smart stuff in at the beginning of the week, when you can also take dirty laundry home. Then for the rest of the week, you won't have to cart bags of clothes back and forth.
• Get the weight off your back - If you are carrying stuff on your bike, you'll be a lot less clammy if you use a rack and panniers rather than a backpack.
• Dress Down - Remember that if you're cycling, you should dress for around 10 degrees colder than you normally would. This alone will minimise sweating. Make sure you've got an extra layer with you, just in case...