I've never heard of a board that has a PCI-E slot and an AGP slot, but boards with one PCI-E slot and one or more PCI slots are very common.
Anyway, you've got a PCI-E slot, congratulations, that's the only slot you'll wanna use when it comes to graphic cards.
There are indeed boards with both PCI-E and AGP slots, but they were not commonly available in North America. When I was shopping around for a board to extend the life of my x1650 a few years back, I had the option of importing a biostar from europe, but it was prohibitive for my budget at the time. At the time, the research I did lead me to believe that the boards were buggy, and it was a good choice not to go for it.
To be sure, you really should find your motherboard make and model, and google it's specifications.