I got the base recipe from "How to Cook Everything" by Mark Bittman. This is a handy volume on just about everything. I don't agree with everything in the book but it is useful. Then there's google for extra tips.
1 pound flour. I used 50/50 bread/AP flour
2 tbs sugar
2 tsp salt
1-2 tsp dry yeast
1tbs malt extract (I used diy dark candy syrup)
For the water 1tbs lye (sodium hydroxide) per three quarts
I have a stand-mixer but you can use a food-processor or by hand.
Mix dry ingredients except tbs sugar
Proof yeast in 150ml tap water for 15 minutes and add remaining tbs of sugar and syrup when hydrated.
Let sit until foaming and add to the dry mix and achieve a dough. The dough should be slightly sticky but very plastic. Place in greased bowl, cover and let double in size then turn out onto floured surface and punch down a bit. Let rest for 10 minutes covered. Then divide into 8+/- balls or equal pieces. Let rest covered a few minutes to relax. Quickly form bagels and let rest again for 30 minutes covered. I suggest consulting google/youtube for forming techniques.
Once the 30 minute count-down starts turn the oven to 400F and fill a pan with the water and add the lye. Watch out this can be caustic. Probably you could get by with less lye. Cleaned my pan very well!
Add the bagels to the pan and boil them 1-2 minutes each side being careful not to crowd them and remove to racks to cool slightly before going into the 400F oven for 20-25 minutes. Salting or topping is done slightly cooled right before going into the oven.
Now what I did was proof my dough slower which increases flavor and improves consistency. Once made and in it's bowl the dough was covered with cling-wrap and placed into the fridge for 36 hours. It was then removed to the counter until it doubled in size which took about 8 hours. This lag was due to the ceramic bowl being chilled and the AC vent blowing nearby.
In the meantime I brewed two batches of beer because I knew the dough would take that long from experience.
The lengthy rise has given way to a very tasty dough and bagel! So the only other variation was the lye water which I adopted from advice on this thread. I can't see myself making bagels without it now.