All very good advice here.
I just want to add that when we housebroke Bailey - we gave her our UNDIVIDED attention for two solid months. Our lives were literally put on hold while we supervised. We kept her in the family room with us. The object was to "catch her in the act" and correct. If she was ever un-supervised (like at work - or to brush teeth, etc.) then she was put in an ex-pen or crate. Never-ever loose in the house unsupervised.
It wasn't easy. All the household chores were put on the back burner (well, that part was easy
). But, all our attention was on the dog until we saw serious signs of success - only then did we lighten up.
Good luck.