First of all, you don't need those kits. No need to shell out a lot of money right away. Later on, when you're more comfortable with Poser and what it can do, you can consider buying add-on content. For now, keep your money and learn to use Poser using the content that comes with the program.

The best thing you can do is to look up the tutorials by Dr. Geep. He's got literally thousands of Poser tutorials, from very basic to quite advanced.

Oh, and as for content, there's a LOT in freestuff. Most of it is for the Victoria line of figures.

You can download Victoria 3 Base and Michael 3 Base for free from www.daz3d.com, that'll get you two adult Poser humans.
Many addons for Victoria 3 and Michael 3 state that they require the head morph and/or body morph packs. That doesn't mean they're totally useless with Victoria 3/Michael 3 base: the textures will work perfectly, only the morphs (the things that change the head and/or body shape) won't work without the morph packs.

Check freestuff here and on other Poser sites. There's a LOT of stuff, some of it is of great quality.

The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter

My gallery   My freestuff