If you are doing the trenching and burying of the cable, I suggest you use conduit. Especially if you are using aluminum (which is a lot cheaper than copper) since it is fairly reactive in the presence of electricity and water. I bought a house that had an outbuilding that was fed by direct burial aluminum. The insulation apparently got nicked during installation and the power failed. The failure point was pretty amazing - it looked like it was eaten away by acid (which I guess it was). The guy I had fix it told me that it's pretty common because an insulation nick is really easy to do and very hard to see. I replaced it with aluminum in a conduit because that was significantly cheaper than copper.

A number of years ago I had the same thing happen on the service to my house from the transformer. The power company guy had top dig almost 6 feet to get to the cable. Glad I did not have to do that job.

George

+1 on the conduit. Direct bury wire is an accident waiting to happen if you ever want to dig a hole. At least with conduit you hear a crack. Direct bury you see a spark and feel a *ahem* slight tickle.

Code around here is 18" bury for secondary circuits.

Conduit is a definite. Not sure how soon I'll be getting to this now considering it's at the freeze point overnight now. Might be waiting til spring now.

So I'm going to at least start running wire inside my shop so I'm ready for insulation and the rest of the wiring. What kind of wiring should I be using? Any tips on how I should be wiring the inside?

On the second you said conduit was a definite. If you are running conduit run single strand wire through it. The size of wire would vary depending on how much amps you would be pulling and maybe how far from the box. Under normal circumstances use 10 gauge wire for 30 amps. 12 gauge wire for 20 amps and 14 gauge wire for 15 amps. Personally I don't like 14 gauge wire and only use it for lighting. Outlets and equipment I use a minimum or 12 gauge wire.

Woodworkers should NOT give electrical advice. I will only say what I have done and it works well for me.

Run separate circuits for lighting and power tools, 14 Ga wire for lights with 15 AMP breakers and 12 GA wire for hand held power tools and "some" stationary tools like a dust collector. Keep the larger motors, 1 HP and up on their own circuit with nothing else on it. If you have the lights and the tools on the same circuit and you trip a breaker, you will find yourself stumbling around in the dark and you may get injured.

As far as 220/240 volts and motors 3 HP and under, I use 12GA wire for the hot legs and neutral. Each tool is on it's own circuit. For 5 Hp motors I use 8 GA. All wires are copper NOT aluminum. All runs are under 50 ft.

That's what I do. Others may have a completely different response.

I had to learn about electricity when I learned about HVAC, not an expert, but extensive knowledge. In my shop, I ran outlets, three to one breaker, lights, all flouresent, two breakers, one each for each side of shop. all those were run in 12/3. 220v circuts were all run with 10/2, and all machines have a serparate CB. DC is on separate CB circut also. I ran a 50 amp circut from my main house panel to my shop and had a subpanel in the shop. That was also grounded properly with it's own 8' rod, I used #6 copper to my shop in conduit, less then 50 feet. Have had no problems and never tripped a CB. I wish I had a pic of how the shop was wired prior to my buying the home. No outlet or light was grounded, it had two circuts for the 28' x28' shop, and one 220v circut that was wired before the power entered the two fuse, fuse box. Screw in fuses. No protection what-so-ever on the 220v circut. I scrapped all that, had to ground all outlets and light, separate the light circuts into two. Cut and separated outlets, ran new wires. All the electric had to be added after the final inspection, when the shop was built, because the electrical would never have passed.

I'm only running the wiring inside the shop for now. Basically from a central location to each electrical box. This way I can go ahead and insulate and not worry about running wires after its already insulated. It was 24 degrees today and even running my heater, it only got to about 43 in the shop. Need to get everything insulated so I can keep some heat in there.

So I have just one thing to say.....14 gauge is rated for 15 amps for a reason. It's rated for 15 amps because it can carry 15 amps all day long...with no problems. Running 10/2 for all 220 circuits is an utter waste of money if it's a 15 or 20 amp circuit. Wiring is rated mainly for amps (until you get well over household voltage). For example, my table saw draws 7.5 amps on 220....it does not need 10/2, nor 12/2.....good old 14/2 will be more than sufficient, by a factor of 2.

If you want to put in the wrong size wiring, by all means, go ahead. But wiring is rated for a reason and using the wrong size wiring would be like plumbing your bathroom sink with 1.5 inch supply lines...it's just not needed.

Otherwise, good luck!!

If you use mc cable inside your shop you will have the flexibility and not have to bend conduit. (Metal clad)

Really the only benefit of running conduit is keeping rodents from chewing on the wire and it makes it convenient to change the wire later if you upgrade the wire. You can just tie the new wire to the old wire and pull it through the conduit. Personally I would just use romex wire running it inside of the wall. It is how your house is wired.

Electrical wiring is one of those things that if you have to ask you will be better off hiring an electrician to do the job.
Nothing against gaining a little knowledge, the best way is to watch a qualified person do the job, getting opinions from here is not the way to go.

It's good practice in a shop to run your lights, on two separate circuits. That way if the breaker trips, you won't lose all your light. It can be dangerous fumbling around in the dark trying to turn off a running tool.