Completely new to LR. Been using PS/CS2. Pulled a picture (JPEG) into LR, and like the processing, but could not figure out how to crop, sharpen, or save-as. Used, process with PS to crop and sharpen. But then PS would not let me save-as JPEG. It arrived in PS as a TIFF. Of course, I did not read the instructions yet.
Look at the tabs or modules -- Library is for sorting, meta-data tagging, coding. Move to develop module for crop, sharpen. Save-as is export. You are applying data-base tracked changes to a RAW file, and then exporting to jpgs.