+1 or 2. I keep 2 pairs of shoes @ work and alternate them. Desenex or Tinactin spray w/odor-eater inserts keep them from getting 'gamey'. Several pair of extra socks, t-shirts, pants, shorts, etc. assure that I always have dry clothes, shoes to change into upon arrival. Working in a warehouse environment doesn't require me to dress 'office acceptable', so I'm fortunate in that regard. We're, also blessed w/lockers and showers. The main rule of thumb I adhere to is not not ride in my work clothes or work in my ride clothes. It's been a bit of a pain in the past as I haven't always had 'great' changing facilities, but cycle-commuting as a lifestyle choice has always been important to me.

BTW, if you want clipless cycling shoes that wont 'click' you'll need to get touring shoes. Lake, Cannondale, Specialized, Shimano, etc. all make touring shoes. Thin spd cleats and deep recessed mounting plates combine to make touring shoes 'click-free'. An above poster is correct in that they all will wear down to the 'click point', but it can take years depending on the material of the sole. Some models of touring shoes are basic black which can be worn in an office enviornment. Others have understated slate-grey/blue, purple, red, etc. combos. Some are Tan/burgandy/black. All can be worn as 'office casual' shoes. Figure on spending at least 100.00US w/cleats unless you find something on closeout.