I agree completely with everyone who has sung the praises of this forum. In thinking about it, I realized I initially began my Tarot journey taking a correspondence course. I'd all but forgotten!
When I first became interested in Tarot, there weren't nearly as many resources as there are now. Tarot seemed so complicated! I just didn't know where to begin. If Aeclectic existed, I didn't know about it. To help guide me, in addition to buying a couple of basic Tarot books, I became a member of the American Tarot Association and took correspondence courses with them. In that program I had a mentor and, at least at the time, ATA offered additional avenues of support all of which helped direct my studies. Later, I took some great classes at the Omega Institute with Mary Greer and Rachel Pollack. Then came Aeclectic, a couple of Reader's Studios and, most recently, Dan Pelletier's wonderful audio-book entitled "The Process".
I have no idea what ATA is like now but lacking access to all that Aeclectic currently provides its members, it truly provided me with an invaluable foundation in understanding and forming a relationship with the cards. All of the learning approaches I have participated in have, each in their own way, expanded my Tarot horizons.
In terms of learning Tarot fundamentals, though, I work best with some structure so the ATA correspondence course proved to be a good fit for me. It provided the form and direction I sorely needed. Later on, I really benefited by attending classes in person. Aeclectic has now opened the door to the world wide Tarot community providing a safe place on the internet to connect, learn and grow with kindred spirits.
Even with all the educational opportunities Aeclectic affords its members, I can see that in terms of building a firm foundation in Tarot, a correspondence course may benefit some people. It certainly did me. That said, there ARE lots of online resources currently available to students of Tarot that cost little or nothing. For anyone seriously considering taking a Tarot correspondence course, I would urge you do your homework before committing your time and money. Ideally, access one where you work closely with a mentor and that doesn't cost an arm and a leg. If, as at least used to be the case when taking the ATA courses, there are opportunities to connect with other students as you progress through your lessons, so much the better.