When do you decorate the venue?

Find out if you can hire a DOC. Depending on what you can find in your area, some will provide day-of setup and takedown help for far less than typical wedding coordinator prices. I wasn't able to find that in my area, but I sure wish I had; I am in the same boat as you.

I've had many friends and family members offer to help, so while I feel guilty about it, they did offer and I will be leaning on them for their assistance. I am trying to spread it out so nobody feels like they had to do ALL of the legwork for setup.

Also, my photographer has offered to do cleanup for an additional fee.

You'll either need coordination services, or find someone else to help. I have a DOC and will give her a detailed description of where I want items. I'm keeping my decor very simple for this reason.

Some venues may allow you to go in the day prior, but this is only possible if there is nothing going on that day.

We are able to get into the venue the day before to do a lot of the legwork, but we also hired a day of coordinator to help with the rest of the decor, lighting the candles, etc. and making sure the day runs smoothly. She will also put together a full day of timeline that will be helpful. They're always worth the extra cost if you can swing it!

Your contract usually states who does what. In ours, we have 12 hour access to our venue (6 hour event time). Our caterer will set up table & chairs, florist will set up flowers, and our day of coordinator will set up other decor & help everyone else.