Should I buy scales to keep a record of my weight loss?

I am planning on really making a big effort to get rid of some excess. I am slightly overweight and not comfortable with this as it is has snuck up on me and will only increase if I dont get ontop of it. I have been dabbling on my exercise bike but have now got a daily plan of 20 mins a day so I am hoping (assuming?) I will see some weight loss results.

I am wondering if making a note of weight weekly on scales is a useful way to monitor weight loss or if taking my measurements would be more effective?

I am going to need to see results to believe it is possible to shift the fat. If I took measurements what measurements should I take? – waist, thigh, calf?

Thanks