There's nothing wrong with doing something every day, however, you can alternate hard and easy days, and your "something" could be a walk at lunch on days when you really don't want to do anything. Just to avoid burnout, I mean.

For example, my schedule is something like this:
M - 60 minute spinning class / 30 minute walk at lunch
T - 90 minute spinning class (now that it's dark when I get home)
W - rest day / 30 minute walk at lunch
Th - 30 minute walk at lunch / run 3-4 miles
F - long ride (30 miles)
Sat - run 3-4 miles
Sun - run 3-4 miles, or ride 15 - 20 miles

Somehow I am supposed to fit swimming in there, but it ain't happenin'.