Firts AG question(s)

I'm pretty excited to be doing my first all grain this weekend, but, as expected, I have a few questions.

First, I'm doing a pretty basic Irish Red recipe kit from Northern Brewer. It indicates a two step mash schedule 153 for an hour, and 170 for 10 minutes. That means a single step infusion and then a mash out before sparging, correct?

What is most recommended, a batch sparge or continuous sparge. Both seem relatively simple. Is there a consensus here or does it depend on lots of things.

With beers containing highish grain bills (I'm looking ahead to a recipe calling for 13 lbs) the sheer amount of water feels staggering. When you have that much extra water and need to boil down to five or five and a half gallons, how do you adjust your boil time and hopping schedule? I anticipate that boiling the bittering hops for 90-120 minutes vs. 60 minutes extracts MUCH more bitterness. Is this something I should just account for by calculating IBU's as well as boiloff volume in something like beersmith?

Thanks for the help. I'm sure even if I screw a bunch of things up I'm still going to make delicious beer. Goodness knows I've made plenty of mistakes before and have not had one lemon in the lot. I'm just trying to give my babies the best chance I can.

Yes, that temperature change is for the mash out.

I like batch sparging, but many people swear you get better efficiency by fly sparging. If I get the chance to get an HLT and sparge arm, I'll probably try fly sparging. It's one more thing to tinker with, and that's attractive to me. I bet the fly vs. batch sparging has been debated 50 times on here- with the consensus being to do what you like best and feel most comfortable with. There really isn't a "better" way to sparge- it's just works for each person and what they are happy with.

As far as boiling- you can boil down as much as you want, but you don't actually add your hops until you have 60 minutes to go in the boil. So, if I have too much wort (and I usually don't- I stop sparging when I get my volume), I boil until I have 5.75-6 gallons left, and then start my timer at 60 minutes and start my hopping. In my system, I only boil off about .5 gallon an hour, so that's right for me. Your system, though, may be different. The first time is a great learning experience.

Best of luck and don't worry too much.
I would recommend a checklist with your steps, water amounts, temps, etc. And take lots of notes, as YooperBrew said the first AG is always a learning experience. Being new to AG myself I remember I got schooled.

Does fly sparge=continuous sparge? Why would you need a special sparge arm for that. Why can't you just open a nozzle on the sparge water tank and let it pour in slowly but continously?

Also, I heard that if you stop collecting sparge water once you reach your volume your efficiency can drop. Is it too small a difference to really worry about??

Thanks again

By just pouring water in at one location you run the risk of forming "channels" through the wort and not rinsing all of it. I don't fly sparge but if you keep an inch or so of water above the grains, and diffuse the pour with something high tech like a coffee can lid it can work.
Stopping on volume means you may leave unrinsed sugars behind, going over volume means you have more to boil off. (A real pain if you do AG on a low BTU electric stove like I do). It's a compromise between the two.