I am new to all of this, in fact I am still waiting on my poser program wich should arrive any day now, but I have been browsing the Renderosity site and learning all that I can in advance. I notice a lot of poser products seem to be geared for specific characters like Michael and Victoria and it raises the question...are these characters required to use these products? If so where do I find these specific characters? And more so...why does the item only work with the specific character in comparison to products that seem generic or will work with the poser program in general.

Michael and Victoria are a series of characters created by Daz3D for use with Poser. You can purchase them at their site. They are not required products to use poser. There are plenty of characters out there that you can use, ranging from realistic figures to cartoons. The reason some items work specificly with a particular character has to do with the geometry of the 3D object (or mesh) that defines the character. There are utilities that will allow you to port clothes from a character to another with some work, but overall, most accessories created for a character are meant to be used with it.

yeah..it's because the characters are shaped differently..I've been finally going through my archives to get stuff into poser..hair and hats, and really bulky clothing (which is actually pretty rare) can be made to fit other characters, but most of the Mikes are really 'cut', so the normal default Poser (dork) clothes won't cover his chest.
There's a program called 'the Tailor' that can alter some clothes to fit other characters. It's not free, but I've heard a lot of good things about it.
When you get a character, start in Freestuff, and go to Poser, then go by category..default characters will have a lot of stuff, but the biggies are Vicky and Mike, from http://www.daz3d.com. They're not free either. Vicky has a lot of clothes that are good too.

All very good advice given here from people who know their stuff. Not sure if you are starting out with Poser 4 or Poser 5, but I would suggest getting familiar with the program and the feel for using the characters that come with it b4 spending a lot of money. There are not a multitude of free items for the basic Poser 5, but if you are starting out in Poser 4 there are more available free and store items than you could ever use in one lifetime.

And all the Poser 4 characters are present in Poser 5 as well, so everything for "Dork" and "Posette" will fit he P4Nude Man and P4Nude Woman :o)

Thanks for this info ernyoka1 ... due to my lack of interest or knowledge of Poser 5 I did not realize the P4 models are in there.

Every new version of Poser has the previous version's models included. Poser 4 & Poser 5 both also include the ancient and rarely used Poser 3 Characters as well. The Poser 3 characters are great if you need a lot of Low Rez people to fill in the background. They don't take much CPU resources to render at all.