Nothing substantial has changed since these instructions were written. The only thing I can think of is that the links to the tools mentioned no longer work, but, the site still has them. Though there are alternatives to some steps.
Your problem, hopefully, is a Windows problem. Windows does not handle removable media with multiple partitions very well. And when running the partitioning tool, you need to make sure it is run as an administrator. From memory, the last time I tried this, I pretty much saw what you are seeing. I used Drive Managment to check the partitions were there. Then I installed the card, made sure everything was working and then used one of the options in
Magic Memory Upgrade Mod to expand the books partition.
Does anything happen when you turn the device on? There should be a power light and it should flash. Make sure you charge the battery. No matter what state it was in before, you should assume it has been discharged.
As you have two Mini's, have you tried booting the other from the new card? Or the non-working one from the other's card?