I'm coming up on my first Chrismation anniversary this week, so my catechism process is still quite fresh in my mind. Basically we met once a week and worked through a wonderful book called "The Mystery of Faith" by Archbishop Hilarion Alfeyev, using it as a way to communicate the basics of Orthodoxy as well as a jumping-off point for other topics our priest wanted to cover. It was very informal, conversational and paced to the needs of the inquirers. I think it ended up being around 9 months of this before we were actually chrismated. But it went by very fast!
I'm sure it's different from place to place, but I'd imagine this to be fairly typical. We'd throw on a pot of tea, cover what needed to be covered and had some great conversations. I encourage you to embark on this journey!