I would like to cast my vote in favor of fermenting in small (1/2 or 1 gal) batches when you are first starting out. That is what I did (I made 15 batches my 1st year of cider making; all but the last batch were 1/2 or 1 gal). I wanted to experiment with different juices and different yeasts, changing only one variable at a time. I learned with my very first batch to NEVER use a yeast nutrient. When your first batch of cider tastes like battery acid because you fermented out all of the sugar at lightning fast speed (like I did), you will be glad you have only a 1/2 or 1 gal rather than 5 gallons of battery acid to drink!
Working in small batches also allowed me to do a side-by-side comparison of 5 different store-bought, pasteurized juices (with all treatments the same; only the juice differed). Ideally, I would use fresh-pressed juice (preferably from true cider varieties rather than dessert fruit). The reality is that I work with what I can get. In January, all I have to work with is store-bought, pasteurized juice. Nonetheless, I learned from my experiment that there is a BIG difference between juices (even among the store-bought juices). Two of the five juices made a good cider (in our humble opinion), whereas two of the others were terrible. The last one was somewhere in the middle. Which ones were the "winners" was a surprise; one of the juices that I bought because I read in an on-line forum that it "made good cider" was a clear loser.
FYI: I would NOT use wide-mouth canning jars (at least not during the secondary stage). I use 1/2 or 1 gal glass jugs because the narrow neck gives less oxygen exposure. A wider surface area is fine during primary fermentation, but you want a narrow neck carboy during secondary. [Luckily enough, one of the "winners" in my side-by-side comparison of juices comes in a 5-gal glass jug. So, I buy 1 gal of juice for less than $9 and get a free carboy (a $9 value). I buy a #6 drilled stopper and airlock at my brew store, and it is good to go. And of course, I thoroughly clean and sanitize everything before I start fermentation.]
Cheers,
Dana Glei
Budding Cider Maker in Sonoma County, CA