My Scotts lawn tractor won't start. When I turn the key, it just make a clicking noise. The "book" states it may be the starter or the solenoid? What's a solenoid and where is it located? Actually, what does the starter look like?

Before I can assist you I need more info as to the size engine HP, how old is tractor, Thomas

Follow the red (+) positive wire off the battery and it connects to the solenoid. I would double check voltage at the battery, common problem. I have a series of diagnostics that have been posted prior.

Don

IF you have similar to me (s1642 with a Kohler Commander 16):
There are a few electrical interlocks; if one is 'open', you may get a clicking sound.
One for the lever engaging the mower blades; it should be in the disengaged position.
If it's out of adjustment, try pulling it toward "disengaged" while turning the key.
One under the seat; you must be sitting in the seat, unless you have engaged the brake lock.
One for the brake; press the brake fully and engage the lock at the base of the steering column.
The solenoid is about 8 inches in front of your battery and the starter is attached to
The right rear of the engine and has a single red cable attached to the bottom, from the solenoid.