Welcome to the forum!
First I'm a little confused regarding item grouping.
For example I have dvd's ripped to mkv files that show up very nicely in the movies view. But I have a bunch of video files that aren't movies. I want them to appear under different groupings in theater mode, and not appear under movies. I see a home movies heading but I'm not undeerstanding how to create a grouping and associate the file with it. I'm sure it's easy but somehow I'm not getting there.
MC sorts files for views primarily based on tag information in the files. The easiest method to address your issue is to edit the "media sub-type" tag for the videos. If you have a bunch of home movies, for example, you'd want to edit the media subtype tag for those files to read "home movies," and then they'd show up in the "home movies" view instead of in "movies." You can also customize the views, but if the files are tagged as "movies" they'll tend show up in tag-based views as "movies."
Secondly my video is jumpy. The PC has a i3 4340 CPU, is using the imbedded GPU with an Asrock ITX motherboard, has 8 gigs of ram, 120 gig SSD OS drive, and a 3 TB data drive.
Should I buy a video card or can you suggest some configuration settings?
Try setting the video to "Red October Standard" (if it's not already set to that). ROS should work well on most computers, but if ROS isn't working correctly, there may be some other steps you can take short of buying a video card.
If you can provide more info about your video settings, what type of content you're playing, and what exactly what you mean by jumpy (judder, tearing, how frequently? etc.), folks may be able to offer some suggestions.
How would I go about setting up Amazon Prime? There there a prefered method for doing this?
Not sure about this one personally, but these threads may help:
http://yabb.jriver.com/interact/index.php?topic=86801.0http://yabb.jriver.com/interact/index.php?topic=86824.0The bottom line seems to be that Prime isn't directly supported, but you can work around it using some tools that JRiver offers (launching it through a configured link in JRiver, and then capturing the sound using JRiver's loopback feature)