Hi - welcome to the lovely world of guineas, you will find lots of fab people on here, and lots of great advice.
Give your new guineas lots of time to settle, explore and get used to your routine, they are nervous little critters, but in time will come to associate you with kindness, food, cuddles, and will trust you. They need to get used to the sounds, your routine, what to expect, so you are right to give them igloos and lots of hay to hide in, they only feel safe whenthey can hide away.
I never used sawdust with mine, as was told they were very sensitive to it, it can get in their eyes etc. Not sure what others think. They do tend to wee, poo and eat all in the same place, but some (!) can be trained to use a particular corner of the hutch as a toilet, things will be a lot easier in the spring when you can get them outside, but they are messy thats for sure.
Use a cuddle cloth for cuddles, and nice soft thing, so they can splodge out on your lap and get used to being held. Have a piece of cucumber or handful of grass at the ready, so they can be cuddled and eat at the same time, then they will relax a bit more.
Enjoy them. They are wonderful, friendly, sociable little things. Great fun! :)