Hi Ron,
I agree with Jay but I would summarize like this...

I am in the middle of a building project - my timberframed shop. I was poorly advised by timberframer, who also acted as designer, to proceed with starting the frame BEFORE the drawing package was complete. I kept asking what it was going to cost and he confidently told me $XXX per square foot. and that it was fine go ahead. Well that was very bad advice. He is a very good timberframer, but as I found out, not good as a designer/architect/drawing.

When I finally did get the drawings which were months late, they still left a lot to be desired. I went out for bids and the cost came in 63% over budget. I've had to deal with that, other design/drawing problems, I've had to finish some of the drawing work myself.

Fortunately this was my shop and not my house. It's been tough to deal with and now I'm Raising in February instead of the planned August.

1. Always do the complete design before doing anything else.
2. Use the drawing package to get all your bids to determine the real cost of the project. There are a lot of costs involved that many don't think of up front - Rental equipment, Porta Jon, Dumpster, Raising crew travel and lodging and raising costs, ... If you can, use someone with experience to help you do those cost estimates.
3. If you are not experienced, you need a project manager. You may expect your GC get the best costs for you, but many times that is not their concern or interest. If your GC contract is a "cost plus", then the contractor has no direct interest in keeping costs down. He'll prefer to work with his buddies, or those he usually works with even if their bids are high. You need someone who will look out for your interests and know if a bid is high or not, will get competitive bids if your GC does not, challenge your GC's bids if needed. Your contract should be set up to allow you choose your own subs if needed and the GC agrees to work with them or allow them access to the site. Yes you're have to pay a project manager, but a good one will be well worth it by looking out for your interests, helping to do contracts, working with your to select materials etc. A GC in my experience isn't spending a whole lot of time helping you to select the siding, exterior trim, gutters, plumbing fixtures, tile, flooring, lighting, windows etc.
4. Never let anyone talk you into staring a timberframe before all architectural design drawings are complete, you've been through and honed them, and you've done complete real bidding to come up with a valid cost BEFORE you start any physical work.
5. Design should start with site visit, a lot of discussion and note taking by the designer, a formalized process for conceptual phase so you know exactly what will happen, and so you know they've got their stuff together.
6. The building permit should be in the homeowners name.
7. If you are doing a cost plus with the GC, also have a "no lien" agreement. Have a lawyer experienced in building contracts.
8. If the timberframer thinks he can be the designer - be skeptical. Have they done a project exactly like yours before where it's handed over to a GC after raising? Will their architectural drawing package really be up to snuff? Being a timberframe shop, and being a designer are two totally separate businesses.
9. IF a timberframer is advising you to move forward with a frame before a complete drawing package and bidding(not estimating, but bidding by subs) is completed, he probably needs work in his timber framing shop and is looking out for his interest rather than yours- RUN!

I could go on with details, but I think this answers the question.