TpT Pointers for a Newbie? :)

OK, so I think I'm going to jump in with both feet (that's the best way to do it, right??) and start posting on Teachers Pay Teachers. I'm going to be creating a lot the new few weeks as I'm getting ready for my maternity leave (as well as a tutoring venture I'm still contemplating). I hate to ask about clipart, but I'm such a rule-follower that I tend to freak out at the idea of getting into trouble (usually because I'm the one to get caught...) so I don't want to create and try to post/re-sell things I'm not supposed to.

Are there certain clip-arts that I can/can't use?? I feel sure that I read someone that you need to purchase a resellers license for ThistleGirl Designs... but I don't know about any of the rest of them out there. Does anyone know about DJ Inkers, Lettering Delights, or Scrappin' Doodles?

Does anyone have any pointers on how to start this fun venture off? I love some of the previews I see, but I'm not 100% how to do those either... screen shots in word made to a PDF? (See, I'm just guessing here...)

I'd love any advice/pointers you could send my way... and look forward to see lots and lots of posts with units about reading/writing/beginning of the year stuff soon!!!

Thanks y'all! I love how I can always to turn to this little blog family for help! :)