So I started the SLAE64 course a few weeks back. So far I'm enjoying it. Vivek explains everything fairly well. The price wasn't that bad either. It only costs $149 (USD)
I have some experience with x86 assembly, so I was able to pick up most of it right off the bat. It covers the basics of x86_64 assembly in Linux, which I might add that there are not a ton of resources out there for 64-bit assembly for whatever reason. Realistically, the resources are not impossible to find, just more sparse than 32-bit. The differences between the two are not that great, but having a little clarification on the addition of the R(n) registers and address sizes is nice to have.
Anyways, about the course content. There are a good amount of videos that go over the basic x86 assembly instructions like mov, pop, lea etc. The later videos in the 2nd half cover topics that pertain to shellcoding specifically, like removing nulls and implementing crypters. Even though some of the basics are covered, I would recommend at least having basic x86 assembly knowledge. There are some gaps that will need further explanation if you don't have prior knowledge.
The test is a series of seven assignments that you must complete and post on a public blog. I haven't completed them yet and will be posting them here at some point.
All in all I am enjoying the course, I mean its only $149 and you get a certificate when you complete it. If you are looking to get into shellcoding I would give this course some consideration.