Reading the OSM site it looks like there's lots of jiggery pokery involved in sending them your tracks. I'm cycling on a lot of roads that don't appear on the map and it seems obvious to me that if I just send them a track it could be anything - I could be walking across a field or whatever. What I don't understand is how to do the stage that translates that track to something useable.
Its actually really easy and
rather addictive. I've added about 2500km to France in the last 15 months.
I find you do have to split your tracks into short chunks before uploading, or they get downsampled too much. They must be timestamped (this is just a crude way of screening out drawn or map-generated tracks).
You upload it and then, after about a minute, you can 'edit' it. You have an option on the edit page to convert your track to a 'way', which I usually do, then it's easy via a drop-down to assign a road type, number, name to it. Obviously you also have to split it, edit out any rubbish bits, and join it to existing stuff on the map and so forth. In the wiki there's a page of useful keyboard shortcuts for these and other operations, which I have printed out and stuck on the wall near my PC. The most difficult thing I find is drawing large roundabouts (mini-Os are easy).
After the edit your work is visible in one version of the online map, within 5 minutes, and this filters through to other versions of the map over hours, days and in some cases weeks.