I have taken several Excel courses and learned how to use many excellent functions in Excel that allow me to manipulate data quickly and effectively.  Pivot tables blew my mind!  I recommend New Horizons; their classes helped me immensely, and they send you an electronic manual that you can search if you ever need a reminder on how to use what you've learned.  In addition, there are many free Excel tutorials on Youtube that I have been using to keep my skills sharp while I am job-hunting.  These are very useful skills, especially in the workplace; however, I am also compiling data into Excel for my volunteer work at my church while I am unemployed.  My church has an excellent music program, and I am the music librarian for the adult choir.  Our old method of cataloging music put pen to index cards.  There is also a book that lists titles for the various seasons.  It involved a lot of manual looking in multiple places, and was cumbersome and ineffective.  The spreadsheet that I am building holds about 3,000 pieces of music, and I am including title, composer, arranger, publisher, voice parts, season/occasion, accompaniment, duration, and a section to note if it has been loaned out.  I am going to use the filters and slicers to make it much easier for the Music Director to peruse the pieces of music for scheduling.  It is taking a lot of time to hand-enter the data, but it will be so useful when I am finished.  Finding volunteer opportunities is very important to me during this time off work.  I feel better about myself when I am helping others.