Small Engines (Lawn Mowers, etc.): Troy Bilt riding mower wont start, jumper cable, safety switches

Question
Hello,
I have a Troy Bilt riding mower approx 11-12 yrs old.  Last month I had to jump it to start it.  It worked and then 2 weeks ago I had to jump it again, it didn't want to continue running but I finished the yard.  I purchased a new battery to hopefully take care of the issue. Today it won't start at all.  Doesn't even try.  I tried to jump it again and nothing.  I just took out the spark plug and will replace that tomorrow.  Will I have to replace the battery as well?  I am trying to do this myself since the repair shops near me seem so busy.  
Thank you for your time and advice.
kg

Answer
 Hello KG:

 1- Check the Battery for a Dead/Weak Cell. 2- Jump from the Mower Battery Straight to the Starter. Take the Red Jumper Cable End and Put it on the Positive Post of the Mower Battery. Take the Other End of the Jumper Cable and FIRMLY Touch the Large Post of the Starter. There will be Sparks. Does the Engine Turn? If Yes, then Check All the Safety Switches. If the Switches are good, then the Starter Soleniod is Bad. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John