Eight days ago 2005 Suburban would not start. Made a clicking sound when I tried to start it. Jumped the battery seemed fine. Today same thing. Made clicking sound, jumped, started up. Went and bought a new battery. Put it in. Went to start it and the thing made the clicking sound again and would not start. What could it be? Thanks!!

Even a new battery will go dead if the car is running on the battery instead of the alternator.
Check alternator output.
First charge the battery up.
Then check voltage with a meter from Harbor Freight ($3).
Should be 12.5.
The start engine and rev it up.
Should go over 14.
But also clean and grease battery terminals, alternator terminals, and check engine ground strap.