I've been able to maintain a 15-minute mile pace for a while now and am beginning to incorporate a little light jogging during my walk - perhaps 5 minutes of jogging, 10 minutes of walking, etc.

What is the best way to ease into almost all jogging? (after warming up, of course). Do I just increase the jog to walk ratio? I'm not looking to move on to running - but I'm finding it more comfortable to jog rather than walk when I go faster.

I've started to do this as well. I was walking at 4mph for 35-40 min. on my treadmill. I started to jog for 3 min. then walk and so on. I then went 5 min. and then continued to walk and yesterday I was able to jog for 10min then walk the rest of the time. I warm up?{at 3.8}for 5 min. then start to jog at about 4.5mph. I would just gradually up your jog time, like you suggested. That's what I did and it has gotten a lot easier to do.

You could also check out the Couch-to-5K program. They have a 2 month exercise sequence that gently moves you from walking to running using intervals.

Exactly. Run when you can, slow down to a walk when you get tired, go back to a run when you feel that you can. Etc. You don't need to push yourself; it will come.

I'm not sure what the difference is between jogging and running other than most folks here use the former, and all the runners I know IRL use the latter. Either at least one foot is always touching the ground and you're walking, or there's a period when both feet are off the ground and you're running-- slowly or quickly, but it's still running.