Thanks everyone!!!!! This has been really helpful. I was initially thinking that I didn't need to do the 1RM, I have done P90X a bunch of times, know what I can lift, etc. But I think that's naive - I'm actually excited about going through and doing this correctly. I was hoping to whip these off lickity split so I can start as SOON as I get the system, but I don't think that's all that realistic either (I'm training for a half marathon PR - so lots of hard running on the schedule right now). But I'll be sure that I'm ready to go as soon as my race is over (end of October - plenty of time to get the 1RM testing done properly).
I'm also eyeing up the lifting tower thing for the heavy barbell chest work...........
I did my 1RM's quite a long time ago, where the workout manager wasn't quite set up, and there were lots of bugs. At that time, I don't remember what order I did things in, but, it was pretty hard to do online, because the pictures were not there, and I couldn't figure out how to do the exercise with no type of description!
I just took a look (right now)at the 1RM page in the Workout Manager, and it looks great for doing this online, if you have your computer nearby. This is what I'd do nowadays if I were starting with what I know now...
- Go to Workout manager from the forums: Click on Workout Manager, Click on One Rep Max. The 1RM Calculating page will come up.
- Under the 1RM Calculator, Step #1, you'll have a choice of Categories to test(All Exercises, Equipment, Muscle Group, STS)--I'd choose STS because then you won't test too many un-needed exercise that may be listed. I am not really sure there are non-STS exercises there, but, I wouldn't take the chance if I wanted to save time.
- Under the Category, you will see the Sub-Category and it will have you choose a Disk. Choose Disk 1.
- Under the Step 2 heading you can decide how to list the exercises, either by exercise name or by exercise number--->click on your choice.
- Click on "Choose from List"; from this pull-down menu, click on the first exercise in red on the list. There will be a video clip demo-ing the exercise-that is the coolest thing, then you know exactly how to perform the exercise!
- Pick up the heaviest weight you can perform the exercise in about 10 reps(I think those are the original instructions) and perform the exercise.
- In Step #3, just enter your numbers (weight and reps) and your 1RM will be calculated then update on the chart on the right side.
Now, just continue with the next exercise in Disk 1. When you are done with disk 1, go to Disk 2 and so on until all your Disks are completed.
Hope this helps, and hope you have fun!

Also, good luck with STS! I'm on my 3rd time through now! You'll find you may even keep changing your 1RMs as you go through each time(you get a little stronger).