I generally like to do it same-day. Its good to start out with a good 10 min in cardio, then do your strength training and then come back to your cardio. This gets your heart pumping and primes your body for a workout. I like to take days off between my workout, otherwise I really get burned out on it. Also, work different muscles different days. Example: Tuesday - Arms/Chest/Shoulders, Thursday - Abs/Back, Saturday - Legs. This helps me cycle my workouts so I don't get bored with them (seeing a trend here? haha) and its good to give your muscles a break. Too much info?