See also The Advantage of Knowing Joseki where the subject is wildly debated.
Comment: I wonder if joseki without some fuseki is almost useless[1].
Charles If you have a problem with corners dying - for example in handicap games - some sensible joseki plays can get you off to a better start. But after that you should learn something more in the way of principles - influence is important as well as territory, the reasons not to be shut in - which are fundamental fuseki ideas.
footnotes
When I was learning go I got a 2-dan to give me 7 stones with a free corner by placing a ponnuki shape in the center.
Since I didn't know joseki, White 5 was a surprise. I was supposed to play at 9, but I chose 6. That was a surprise to him. ;-) I don't remember the gory details, but he lost the corner and resigned. :-)
I didn't study joseki until I was shodan.