If your really into learning maya sure the class cant hurt ,but just make sure there not telling you there gonna teach you maya in a day...cause that will never happen.See what its about cause if you have the books and tutorials ,that will help .Of course learning from someone helps,thats what i`m doing right now.I go thru the books and then i see the difference in how my teacher does it.Its just comes down to different ways to the same end.How long will it take for you to get proficient in maya is up to you but i always see 2-3 years experience with it on job postings????so good luck .If i come across anything else i will post it here.Ralph