When I ran my last race, I turned on my running to strict 3-4x a week with higher intensity levels, while continuing my strength training. I tracked speed, time splits, heart rate. Then the week of the my race (it was a 5K, nothing crazy), I ran easy (0% incline indoor or lower heartrate when outdoors) and skipped all my leg workouts. If I do a longer race, I'd run shorter distances the week of the race.
As for weight training, I do believe in taking a week off once in a while. Back then, I'd just not lift and continue my cardio. My last "week off" coincided with a twisted wrist and a sprained ankle. That was a very tough week for me as I couldn't really do anything besides pushups on fists and very careful neutral grip pullups.
Currently, I'm pretty lax about cardio, so my future cardio weeks off will probably be scheduled around races I plan to run. Weight training weeks off would probably be every few months or so while cardio stays on (maybe when I go vacationing, which usually includes eating!)