Issue 4 - Housebreaking
Take the time to read the following - even if you are a savvy dog owner, some of this may not have come to mind and/or are good reminders. Please note that many suggestions are Leo specific!
If you feed your puppy at about the same time every day and let him out to do his business right afterward, after every nap, first thing in the morning when he wakes up (you have to be fast then) and last thing at night, he will very quickly know what is expected of him and he will be housetrained in no time.
Crate training - this means to have him sleep in his crate for any nap and overnight. Usually, puppies will not soil or wet their bed and will let you know by whining or scratching that they will have to go out. It is even then the best to instantly take him out when he wakes up in the morning or from a nap.
Overall positive reinforcement is the key to training so praise him whenever he does anything right. You can never praise him too much.