TexasCHLforum.com

As others have said, there are a few basics and from there it is a personal decision considering comfort, accessability, etc... As to the basics, do get one or more good gunbelts, do find a quality holster (IWB or OWB is one of the personal preference issues), and do dress around the gun. The search function is your friend for discussions of belts, holsters and also dress ideas. Now, as to your questions...

"I am thinking that IWB will be the most 'invisible' to the casual observer. Is that a correct assumption?" Answer: The IWB MAY be less visible depending on gun, belt and holster selection, body type, and clothing choices. OWB "Pancake" style holsters seem to present a viable alternative to IWB in many cases.

I want accessibility but as much invisibility as possible. Is this like wanting ice cubes in heck? Answer: Not necessarily. Accessing most IWB and OWB holsters is complicated by the covering garments more than anything else. In most cases, the grip area of the gun is above the belt line making the gun easily accessible once the cover garments are out of the way.

If I am using an IWB where on the WB should the holster sit? Seems as if it's right on the hip bone then it will stick out the farthest. Should it be somewhat fore or aft of the hip bone? Answer: For IWB, the holster should sit where it is most comfortable while being fairly concealable. Each persons body is a bit different, and the choice of firearm and holster may play into the comfort. Some folks prefer cross-draw, others a strong side front position, or strong-side side or back position. If you search, you will see that most folks have arguments against small-of-back carry, but each person needs to weigh the options to see what best fits them. Note, that most of the highly regarded IWB holsters (items like the CompTac MTAC, CrossBreed Super Tuck, Tucker Anser, Galco King Tuk and the like) are adjustable for cant over a pretty wide range, but may require a special ordering option if you want to carry cross-draw or reverse-cant at all.

Best of luck finding the option(s) that best suits you.