Hi metrivers,
You can add a slider by going to Appearance > Theme Options and clicking on the Homepage tab on the left. Scroll down to the Homepage Slider section.
The quickest way to get up and running is by selecting the ThinkUpSlider. Click Add Slide. Click on the + icon to expand the slide options panel and then click Upload to add your image. The other fields are optional (title, description, url). Repeat this for additional slides.
Don’t forget to set a Max Height for your slider based on your tallest slide. I find it is best to crop all of your slides to the same size before uploading. Save your options and you should be all set.
Hope this helps.