If you prefer editing on a google map my website
www.gpxeditor.co.uk might do what you need,
to start you off:
Right click -> Load
Then to delete part of it:
Right click on the track -> Edit -> Cut to start/end
To join a track up to another:
Right click on track -> Continue drawing
Draw it to within 100 yards of the start of another track, then when you right click on it you should get the option to merge it with the other track
Also if you load another file when you've already got tracks showing it will add to them, not replace them.
If you then want a route, you're probably better saving the track and importing it into something else for the time being, the create route needs a bit of improvement as it doesn't handle large monolithic tracks that aren't split up into segments that well yet, but this should improve soon.
You can save off individual tracks (Right click (on a track) -> save just this) or everything showing (Right click (not on a track) -> Save All) if you want to import it into something else to convert into a route.