Aminoacyl-tRNA synthetase ribozyme, an example of the RNA-based catalysts that may have preceded protein enzymmes during the origin of life.
The Museum of Science at Boston has a fantastic interactive web resource on the origins of life. Exploring Lifes Origins has a timeline of lifes evolution (with sliders), and pages on understanding the RNA world and building protocells, with a nice animation of protocell replication. The pages have been made in collaboration with ribozyme guru Jack Szostak and his laboratory, and there is a handy resources page for educators.
If you are interested in our current understanding of the origin of life, this is a very handy starting off point. You can explore ribozymes in more detail with proteopedia.