Checking the scale all the time isn't a bad thing IF it doesn't drive you crazy, and make you want to quit. If it is having that effect, it is best for those particular people to not weigh so often. It is a personal thing.
I recommend, if you are driving yourself crazy with the scale and getting too frustrated, that you give the scale to someone for safe keeping. If you have a husband/boyfriend/daughter/friend who you see often, have them only give you the scale once every two weeks.
As far as nonscale motivation-get a clear jar/container/bank, and put a quarter, dime, or nickel in for every workout, and for every day that you eat on plan. If you can, put one in for every difficult temptation you made it through (going to your friend's house, and not having the cake she put out on the table). So, you have the potential for 2-3 quarters each day. Watch them grow, and when the container is full, cash them in at the bank and buy yourself something frivolous. (I am always surprised at how much that small container of change actually adds up to!)
Basically you have to find little creative ways to keep yourself motivated along the way.
