It really depends on the sport. The only sport where I spend lots of time tracking odds is basketball , that's b/c that's the sport where I have the worst and closest bad beats. I probably check once per hour on hoops.
On baseball I don't spend too much time checking odds (although bases is where I spend the most time capping) I usually make my wagers as soon as I finish capping. The exception is if I like a heavy fav I'll wait to see if it drops.
On football I check once a day sun-wed , and then every hour or so starting Thur afternoon.