If you run a short-ram, I'd actually leave that on as it will draw more warm air from the engine bay than even the stock setup.

Make sure your coolant has the right amount of antifreeze (should be 50%), they sell cheap testers at many stores, very easy to use. Otherwise you could just drain and replace the coolant w/ the proper amount if it's old anyway.

As well as checking the battery's output (or just replacement), I'd take a look at your belts to see if any are on the loose side or are full of cracks. They tend to be more likely to slip in cold weather.

Good idea to change your oil just as it gets to be cold out, so you have fresher oil (of proper weight) during the winter - as it ages it tends to thicken up more when cold, or so I've read.
On those civics, I believe you can run 5w20, which performs very well in the cold. Not sure if it says that in the manual/on the fill cap, etc. though. As long as it's of the 5w variety you'll be fine. 10w30 would be fine also as long as it doesn't regularly get below 20.F where you live, or if it's synthetic.

Make sure you keep your tires at the correct pressure and that they have enough tread, best to have the 2 tires with the most tread on the front.