Congrats on your RX. You can sign up at Lexus.com to verify the services and updates performed. It'll also list any that are outstanding. Two that come to mind are the iPod scrolling fix
and gas pedal modification
. And most recently a software upgrade
related to the gas pedal modification. Again, this information should be listed on the Lexus owners website.
I'm familiar with Helm. I used to have them for a previous car. But I'm not sure if they have any repair manuals available for the RX. A few people have mentioned a website where they were able to subscribe for a short time to find what they needed. They'll have to chime in. There are a few DIY threads here.