All very good advice here!!
Here's my two cents - potty training and living a normal life don't go together!! But, if you can spare a few weeks and give the puppy your undivided attention (using the advice in this thread) you will see results.
The most common mistake is that owners do other things while the puppy is loose in the house.
Block off a room and watch, watch, watch the puppy. If you have to turn away to do something else (i.e. watch tv, wash dishes, brush your teeth, go potty yourself
) then put the dog in a crate. During potty training - the dog is only allowed freedom when it can be watched.
Yes, it is frustrating and time consuming - but a few weeks of dedication will result in a life time of trust. Believe me this works, Bailey was trained at 4 mos and reliable at 6 mos of age. Heck, she even rings a service bell when she needs to go potty - its hilarious!!!
For more ideas - get "housetraing for dummies". I used the ideas in that book and adapted my own process.
Good luck!