The problem with Blender is that it has a complex interface and takes a while to learn. I tried reading the Noob To Pro wikibook but didn't get very far.
I suggest
Wings3D.It is free, and more simple to use.
I also suggest
Milkshape 3D.
Though it costs ~$35, it is the most simple and easy program I've ever used and also has the required .dts exporter.
Which by the way, .dts is the output filetype needed for Blockland (if you're into modeling for add-ons). Blender also has one I believe. Wings3D does not, but you can export .obj then import into another program then export to .dts.