Two slicing programs to start with are Cura https://github.com/daid/Cura
which is supposedly a little easier than slic3r http://slic3r.org/
... but I haven't used Cura so that is hearsay. Slic3r used to be straightforward but there is lots to tweak now which can distract a new user. It's a shame - slic3r used to be so straightforward. In fact grab an older version like 0.7.2b or maybe a late 0.5 release so you wont be overwhelmed with options. Generally the quality from these versions was great with very little knowledge.
For PLA you only really need a fan to cool the layer before the head comes around again. I find nozzle mounted fans are not foolproof for first timers - it's easier to just start with a desk fan (I use a case fan) that blows across the bed onto your print.