Trying to learn the ropes, I decided to stick to "career mode" and still max science without going out of Kerbin SOI. So, I visited all KSC with a science-gathering plane, twice! Once to directly collect all science (you can put all experiments in a "custom action group" and with a click of "1" you get all 7 experiment reports). 32 biomes around KSC took me ~30 min and yielded directly ~2k science.
The second round was with a docking-capable plane to put all experimental data on a mobile lab satellite. Just the KSC biomes use almost 500 of the 750 data storage units and after putting that satellite in orbit, it now grinds out ~6 science per day for additional 2k science.
Next on the to-do list, visit the other Kerbin biomes (badlands, polar caps, etc) for science gathering in flight, landed, low and high orbit, but the suborbital hopper is not so easy to build sturdy and lightweight...
When I get that routine down: off to Mün ;-)