The chief attraction of weights so far is that I can do it inside when it's wet out. Observations made so far are

Legs:

• I don't have enough weight for two-legged squats
• If I were better balanced I wouldn't really have enough weight even for one-legged squats, but the wobble adds an extra challenge to it.
• The noise from my knee is disconcerting
• but appears to be unconnected to the pain in my knee which develops if I squat (on however many legs) without warming it up thoroughly - and I mean ten-minutes-running-on-the-spot thoroughly
• That last seems to be less of an issue than it was when I started, so I may be strengthening my knees this way even if I'm not able to push my quads/glutes to failure
• It's very easy to do too much. "Too much" is here defined as "still feeling it two days later"

Summary: I believe I'm developing some knee strength, but there's not yet much evidence that I'm getting any actual go-faster-muscle bulk. Too many reps, not enough mass for that, but anyway I can't do that until the knees can cope.

Arms/upper body:

• really only doing these because I'd quite like an upper body. Not expected to help with skating, unless perhaps that when I take a dive forwards onto my hands they may make it less likely I spread the load onto lower face and teeth
• dumbbell "bench" presses on a swiss ball are a great core exercise
• but way easier than the fly
• am unwilling to exercise to failure, because I'm doing it on my own and don't like the idea of being knocked out by my own dumbbell when it falls from my limp rubbery hand. But can exercise to "really don't feel I can hold this any more" and still not hurting the following day. Odd

If you know as much now as I did a month ago about this stuff, Wikipedia has pictures