>>3301078>And am I correct in understanding that the developer I selected mixes to make 1 liter of developer?Depends what you bought, it comes in various sizes, the smallest being 1L.
About mixing, there'll be instructions printed on the bag. In general, there are 2 bags of powder, and you warm water up (40-50ºC), mix the one bag first until it's dissolved, then pour in the powder from the second bag and stir until it dissolves. And finally leave it a couple hours to cool down to room temp.
>(and four rolls of 135...that sounds like very few)It can definitely do more than that.
I use it one shot, i.e. mix with water and discard after use.
There are many dilutions you can use, most popular ones are 1+1 or 1+2.
In 1+1 you mix one part water and one part developer to make up the final quantity (I guess ~300ml for a 1-reel tank), so you end up using ~150ml per film, so 6 or 7 films overall.
In 1+2 dilution you'd mix 100ml of developer with 200ml of water, so good for 10 films.
The times are different (longer) the more you dilute, but apart from being far more economical, they usually look better too.
(more dilution--->sharper grain but slightly bigger).
I only use stock (no dilution) when I need to push film over 2 stops or if I have to process a shitton and I'm in a hurry.