Hello, Photoshop CS or Elements & Lightroom are pretty much industry standard software for working with photos these days. If you are a digital photo pro or graphics person, scrapbooker, etc. you pretty much have to know PS or an equivelent (which in my opinion, there are none, but that is only because I know PS best).
There are classes offered at any self respecting art or vocational school and most community collages, but they can be pricey and time consuming. Don't forget there is a lot you can learn from library books and online resources for free. I just added a resource on this blog offering some tips on PS that you might find helpful. Please check it out in the side bar.