Being a Daz Studio native and having no aptitude for Poser, I can't be too helpful with the Poser learning curve because while the programs share a great deal of compatibility, they also have some very different features and capabilities. Both programs are well loved by their users though and produce beautiful and satisfying results.
As you already have Poser, I'd say give that a go first. There are a number of outstanding books and tutorials available for Poser (this is one of those areas where Poser really outmatches Daz Studio -- there is much less available in terms of learning material for DS >.< ) to get you started.
Also, while you're getting your feet wet, I'd advise taking advantage of some of the free content available before making too deep a monetary investment. We have some very nice free stuff here, there is a lot of very good free stuff over at Renderosity and of course, Daz gives away their base human figures and a lot of other really nice stuff on their site. There are other good, reputable freebie sites around as well that you'll find as you make your way around the poser/daz community sites.
Once you get a taste of the programs and the community, you'll find it can be a bit habit forming (after the overwhelming wears off). Should you find yourself enjoying this new hobby and community, you'll know better what it is you want and we'll be better able to help you find it (and more than happy to help you go through your monthly content budget LOL!!!).
If you aren't already, get signed up for the PA2, Daz and Renderosity newsletters. You never know what kind of deals you'll be missing if you don't (and the deals are usually pretty sweet -- including nice limited time freebies in some cases).
Anyway, welcome to your new addiction and to the poserverse.
*hugs*
Wayii
