Do you hand off the project and pray or do you take it on as the GC (General Contractor)?
For us, I really wanted to "have a hand" in the project. Trying to find a GC who would let me do parts of the job looked very unlikely so I finally talked Wendy into letting me be the GC. That meant I'd find and hire all the subcontractors who would do the work. This would save us money from typical GC markups and allow me to feel like I was more in control of schedules and fate.
Everyone says you should get AT LEAST 3 recs for every contractor (that includes architects as well as builders/GCs). I did that and learned there's a lot of wiggle room. I had architect quotes that varied by $3K and builders who said it'd cost around $120K+. One plumbing estimate was $4K higher than another. We are only adding 1 bathroom and a washing machine drain!
Getting multiple quotes, asking for referrals from friends/family, and just calling up folks helped put perspective on the costs. What it didn't do was give me the TRUE picture of how things would work once we got started. Signing a contract with a sub is easy. Slotting them into the project when you need them to show up is not easy.
I now see why folks say it's a painful process... and it may be an ulcer-inducing puzzle. But I think I'm going to enjoy the pain and results.