3D printer design software?

So I just got my first 3D printer! it's a Tripod style in kit form, with about 4 pounds of tiny screws, so I'm going to be busy this weekend.

I have no idea where to get started designing things, and preparing those designs for the printer. I have some experience with Blender, so I can probably figure out other software. But when I looked online for advice, I found an overwhelming array of suggestions on what to use. Much of it conflicting. And I don't have any experience, so I can't pick out the good advice from the bad.

So I figured I'd ask here. I know a bunch of the members here use 3d printers, and I was hoping some of you wouldn't mind sharing what software you use, or any advice on how best to get started?

SOLIDWORKS
http://www.solidworks.com/

or

eMachineShop | Free CAD Design SoftwareeMachineShop
http://www.emachineshop.com/machine-shop/Free-CAD-Design-Software/page100.html

eMachineShop had some bugs last time I played with it.

There is also a long thread by Nechaus about world domination with 3d printer that has lots of great info in it.

I too bought a i3 prussa clone called the anet a8 from gear best. updated it immediately with an induction sensor for the z axis and installed skynet3d v2 firmware onto the printer to get auto bed leveling. Got to say, its bloody excellent. Anyway as for software. I agree with solidworx but i use fusion 360 mostly. I used to use sketchup8 but it produces questionable stl output as its not a nurbs based 3d modeller which are better for the slicer software (which i use cura).

Currently making bits for a 3d router called the mostly printed cnc. i am 4 hours into about 108 hours of printing.

I've been happily using Design Spark and recently started to try Onshape as there were many limitations to Design Spark as it's free.