For the inherited IRA, I had to provide a death certificate (the funeral home asked us how many we needed).
Then we contacted the holder of the IRA (it was Fido, and I was staying with Fido) and the adviser walked me through the setup of a IRA BDA (which is how they title an inherited IRA, and in the details it contains my father's name). My sister sent in the death certificate, so I just had to reference her name since the agent was already aware of it, so you may only need to send in one and have the rest of the siblings reference that one, but do check in with the agent/rep to make sure of their procedure.
This is what I had to do:
First, opened the IRA BDA account, empty for the moment;
Then I was to send in a letter of instruction directing them to move the portion of my inheritance (mentioning that the main account listed myself and sister as 50/50 beneficiaries), and the account numbers for his account and my newly established inherited IRA account along with a copy of the death certificate (sent in with my sister's letter of instruction).
They handled the subdividing and moved my portion over to my inherited IRA account within about 2 weeks - may have been a bit less than that.
I then established an automatic RMD (my dad had already taken his for the year, so it was to be effective starting the following year). I had them withhold federal taxes to avoid a huge tax hit, since I wasn't sure just how much in taxes I'd be hit with overall during the settling of the rest of the estate.
All of this was done over the phone or by filling out paperwork and was very easy. And since it was done pretty quickly and they were aware I wanted to leave it as an IRA and just take the required minimum distributions, they made sure to follow all of the steps correctly and easily. I can change my RMD at any time, and have moved the date around some, but for the most part it really is pretty simple, and you just need to talk to Vanguard about what they need and exactly how they need it done.
When they moved my portion of the account I requested they move "in kind" and left it under management for a little while as this was my first foray into serious investing and was still sort of reeling over losing my dad, but I did take control of the account within 6 months and it was perfectly easy to sell off the crummy stuff once I understood what to do.
As far as the house selling... you get a stepped up cost on inheriting this sort of property as of the day of your father's death. So the executor will likely have to name a fair market price in probate that might need to be established through a real estate agent if the property is quite valuable or in poor repair (basically if it's one or the other extreme, otherwise just check the property tax assessment for the most recent year and that should give you a general idea). Don't lowball it, because if it sells for significantly more than the stepped up cost established in probate, y'all could have to pay cap gains since none of you are going to live in the property. Do discuss with the siblings and estate lawyer just in case my info is not completely accurate for your state/situation.
And finally, I am so sorry for your loss. I know how hard this can be, and even if you knew it was coming it still can send you reeling and feel quite overwhelming. You and your family will be in my thoughts.