Here's what they have:
A full panel inside
A main breaker outside in an enclosure next to the meter instead of in the panel
An empty lug panel screwed to the wall inside of their shed (I mean empty; no breakers or anything, basically a metal box on the wall) He bought the panel, but no breakers because he wasn't sure what to get because he wasn't sure what all was going in shed at time of purchase

Here's what they want:
A portable storage bldg approx 60ft from meter turned into a “mini-spa” with a treadmill, tanning bed, a small window unit A/C, several receptacles and lites, and one outside circuit for floods and one receptacle

Is there a SAFE\easy way to either tie into the load side of the main breaker inside the enclosure outside the house or the wires in the attic between the enclosure and panel, to then run them underground to the shed, once in the shed connect them to a disconnect (if necessary) and then\ or to the sub panel they have installed, fill it with appropriate breakers and then wire the shed. I can do all of the work, the only real questions I have are about tying into the load side of the main breaker somehow, instead of getting from the full panel, which is in the middle of the bottom floor of a house on a slab, to the shed; and then not really whether there needs to be a disconnect, but which type is appropriate and whether it should be near the main breaker on the house or out in the shed.

Any suggestions are appreciated and I will answer any questions you may have to help asap.
Also, wire sizes for run from house to shed would be great

Thanks for even taking the time to read all this.

Are you doing this job for someone for pay?

Vrysnky - From what I just read and understand from it , I have the feeling that you are not very capable to do this job without getting yourself hurt or dead or the place burned down NOW - to start with you need to get electrical permits from the electrical co. And find out what the codes are for your area, There will be more then just putting breakers in the box he bought . If I were you I would get a licensed electrictin GOOD LUCK & GOD BLESS < :: F.B.E.

First off let me say that I appreciate your concerns, but I am capable. I have been doing commercial work for the last 7 years, so I know that I am no expert, but I do know what’s going on; and I am familiar with permits, etc. I just have these residential questions because that is not what I do day to day. I am not trying to oversimplify the “just putting breakers in the box he bought” but I do know what to do regarding that, I was asking about getting the power out to the building in a safe and relatively easy way. They have already had a couple of licensed elecs look at it and just asked a friend for an opinion and I said I would give them mine and then get others to come up with the best solution from all suggestions. If I were as naïve and short-sighted, or “shoot from the hip”-ish, as it appears you think I am, I would already have wire strung up and the house would be in ashes by now. I’m just trying to get some ideas to save them from spending unnecessary cash (I can elaborate further if you'd like), but still get a safe and functional installation. Thank you again and please do not look at this as if I am ungrateful or an a$$h@le; maybe I should have made some things more clear in the original post.