There's definitely a lot to it, and you do NEED to be there with her, there is a good chance you will need to step in and you need to know the signs if there is something wrong with her. (IE pushing for two hours straight with no sign of the puppy means GET ME TO THE VET RIGHT NOW) There's a whelping box to build, an emergancy kit to make, phone numbers to memorize (Hello vet speedial number 1) lots to read, cleaning/puppy proofing a room for her that will keep her away from the other animals, nutritional needs that need to be taken into effect for her up until the actual whelping..
Then comes temperature taking, charting, lots of sleepless nights monitoring, and finally delivery!!! Delivery is lovely- lots of blood and gore and counting placentas, and making sure puppies are breathing, and tagging/weighing, charting, clearing lungs, checking for birth defects, making sure everyone nurses and stays warm, helping a stuck puppy, cutting emblical cords if she is too rough, breaking sacs if she is too slow... etc.
..then you get to raise puppies

Stinky, crawling, mewling, but adorable puppies- and there are the problems that could arrise if she doesn't produce enough milk, gets freaked out by the puppies, develops pyometra from a withheld placenta or other reasons and needs to have emergancy surgery and can't nurse the puppies on the medications... so you'll have to read up on tube feeding and everything else just in case it comes to that...
Typically I say have $3000 set aside JUST IN CASE before whelping a litter, mutts are just as expensive as top quality show dogs when it comes to problems when they deliver. It could all go perfectly OK, but then it could not. I remember having two rescue litters whelp the same night, one had 11 puppies and it went perfectly, one after another, no problem, all healthy, great mom. The other had 5, and it was a blood nightmare. Rushed to ER for emergancy c-section, one puppy born mumified, one born dead that I was able to revive and get breathing, hours between each puppy with shots of oxytocin to help her push but still not really helping, and a very very hefty bill.
How far along is she? can she not just be pulled, vetted and spayed? How old is she?