How do I know for sure that time machine is backing up all information from my computer. I am most concerned about my financial program.
You can use the System preferences for it to put it in the menubar. Its little icon will twirl when it is backing up.
Don't use your computer during that time, if you want to make sure the last backup is what is saved.
Alternatively, you can use Carbon Copy Cloner to keep an up to date clone.
Retrieving data ...