In the absence of a Vespa, a convertible VW or a chestnut stallion, a bicycle is a wicked way to get around and feel the sun on your face and the wind in your hair this summer. Make sure everything's still in fine fettle after months in the stable (or that dark, dank storage locker).
In my life, bike tires deflate a little over the winter months while spare tires grow. Planning ahead and putting some air in the tires about a week before hitting the road this spring means there's plenty of time to check for leaks. If your tires are deflated or flat a couple days later, there's still time to get that tube replaced. (If you're pumping up your tires at the gas station, inflate to the PSI indicated on the sidewall of the tire — narrow tires generally need 80-100 PSI and mountain bikes with wider tires require 40-60 PSI).
When worn out tires prevent you from going, that's bad; when worn out brakes prevent you from stopping, that's worse. Fortunately they're easy to check. Lift up one end of the bike so the wheel can spin freely and squeeze the corresponding brake (then check the other end). The wheel should stop instantly. If it doesn't, drop in and see your friendly bike shop.
nuts & bolts
Check that your seat and handlebars are straight and that the bolts holding them are tight. If the handlebars are loose you won't be able to steer. Before you tighten them off, make sure your seat is the right height too (who knows, you may have grown over winter). If the seat is too low, you have to work much harder (when the pedal is at the bottom of the stroke, your knee should be just slightly bent).
One of the dirtiest, but most satisfying, jobs in the bike maintenance list is cleaning the chain. You can get up close with an old toothbrush or take the easier route with a chain cleaner (a little plastic box with rotating brushes in it). Don't forget to lube it once it's sparkling.
A gentle tour of you neighbourhood, before you head across town, is a good opportunity to test your gears (do they shift up and down easily) and your brakes. Listen out for any grinding, squeaking and clicking noises (from the bike, not your body).
I use the mnemonic "Tortured Bikes Never Create Thrills" to remember the five checks on this list. If something doesn't feel right, take it to the pros. Alternatively, local bike shops, like Our Community Bikes in Vancouver, are great places to pick up some knowledge about simple checks and maintenance that we can all do ourselves.