Looking into changing my rear wheel to quick disconnect. How do I find what skewer to use such as dimensions and sizes?

What kind of bike do you? You need to replace your whole rear axle set (axle, bearings, cones, spacers and locknuts) the trick is finding one for your current hub. You may be better off just buying a new wheel with a hollow axle and a quick release (QR) skewer already in it.

Sometimes solid nutted axles are thinner than hollow ones so a QR hollow axle may not fit in the slots on your frame.

You don't necessarily need to do anything but replace anything but the axle and add a skewer. For a given brand the threading and diameter are the same with some rare exceptions. https://sheldonbrown.com/harris/axles.html

The q/r axle needs to be a couple mm's LESS than the current distance between the locknuts on the hub plus the sum of the thickness of both dropouts (including the derailleur mounting plate if you have one. Once you have the axle length you just need to obtain a skewer compatible with that length.

That depends on what kind of hub the OP has and he hasn't said. If it's a conventional nutted freewheel or freehub type, your recommendation is correct. If it's a coaster brake, IGH or other type, it isn't that simple.

Yes, I did assume freewheel/free hub. IGH is not possible and in q/r on a coaster when there's a brake are to detach.

Okay a little info should help
It has 6 cog freewheel system ,17mm long threaded axle , 36 hole hub , the frame at mount 14 mm wide measured outside to outside of frame.Any other info I can give let me know

If it's a 6-speed freewheel the likehood is high that the OLD (over locknut dimension) is 126 mm measure between the inside faces of the dropouts and you will need a 137 mm long 10 mm diameter x 1 mm thread pitch hollow axle and corresponding qr skewer.

Posting a closeup picture of your rear hub might be helpful.

Response to The ARS You sir have the correct answer .I almost forgot my own belief in Dont fix it if its not broken.
Paul

Does not affect the answer to your question - The frame distance is the info you need if you decide to install q/r...and that's CM not MM.

Well, it may be the answer you wanted, but you did not ask whether to change to Q/R but rather how, and one does not spin a Q/R to tighten it!

I have a question about these axles. I actually want to do the oppisite of the OP and put solid nutted axles on some old CampI wheels. I see Wheels Makes a rear axle that uses the existing cones but what about the front? Or does Harris just not stock them?

Campy used M9x26tpi threading so the commonly available M9x1.0 front axles won't work with Campy cones and locknuts. You will need an axle with matching threads.

I am aware of that but I do not see it on the chart.

Probably the best thing is to call Harris and see if they can help. I checked Loose Screw's web site and they list a qr M9x26 Campy front axle but no nutted ones. I wonder if the axle from one of Campy's older track hubs would work.