I am starting to be asked to take pictures for families and I only have the Canon T3i and the 85-300mm lens. And of course the lens that came with the camera. I don't have any other tools and wanted to know what should I start with buying?If you want to get the most out of your camera, use RAW. Nothing wrong with using jpegs but editing them will degrade the quality even further.
Oh and I have an OK software Digital Photo Professional that came with the camera...would like some recommendations for software too! User friendly...something I don't need to take a class on how to use it!
The most powerful RAW editor is Lightroom. Adobe has free video tutorials and there are a ton of good books.
If you just want the software to do the work for you, DXO takes a fairly good stab at developing RAW images, you will probably be happy with them. However, if you want special effects or more control, use Lightroom or Aperture.
You are going to go thru a learning curve no matter what you choose. Many people try to organize their images into directories or folders on their computer. Lightroom has a built-in image management system, but you should learn to use it before jumping in and trying to organize by folder.