Barb,
Without a picture I'm guessing, but most of them are like the old Pall Mall cigarette filter adds:
"Over, Under, Around and Thru"......... well, kinda.
OK, to be serious I'll try to help based on what few pics I have. The thread comes off the spool to the left and through the thread guide. Then it does a turn and comes forward and then drops down the grove on the right side, down to the hook then up the left grove to the thread take up lever, then down again through the guides to the needle.
That's real simple but should be close. I have a Merritt 4622A and it threads pretty much like that. I thought I had some pics of it, but they must be on the dead hard drive.
If you could post some pics of the top and front of your machine I could help a bit more.
Here's a link to a slightly different Merritt, don't know if it will help, but the basics are similar.
http://www.sewusa.com/Threading_Diag...ng_diagram.htm
Joe