(The statement below is made with the caveat that your builder will allow you to use an outsider, and not his own wire guy. Many do not allow outside contractors not retained by the GC on-site).
Since you are going to hire someone to do this, then the time to get them involved is NOW. You will want to select an a/v integrator/installer/whatever they call themselves (after carefully researching backgrounds, checking references, etc) and have them design the wiring plan. Though you can start with a very broad range of wiring if you are unsure what you will want, it will be much better to design the system and wiring up front before construction begins. Since you mention blinds/shades, it's even more critical, as those could require significant rip and patch work to wire power/control later depending on what type of shade or blind you decide upon. In general, plan to run a couple of coax and 4-6 cat6 cables to each room (you will want some for a/v distribution, some for networking, etc.) for a/v equipment alone. But this is just a broad guess at what's needed. Do you want a distributed audio system? That might require speaker wiring and cat6 drops for wall mounted controls, depending on the system you choose. Do you want centralized lighting - that will impact how the electrician runs the lighting wiring. These are all questions that you should be sitting down and discussing now with your selected a/v pro. You might not figure out all the details right away, but at least determining something like "I want central lighting, I want automated shades in this room, that room, etc." will allow a professional to design a robust enough wiring scheme to significantly reduce the need for post-build wiring drops.
There are a number of threads in this section on "wiring". I would suggest you read those, if you haven't already. There's probably a link in one of them to the corresponding section on cocoontech.com about "wiring your home". That will give you a good starting point.
So to take your question about shades - that has different answers depending on the brand and type. In general, you need power and control wiring run to the shade mount location. Some shades can operate over wireless control, so they only need power. And there is a very narrow line of shades/blinds from Lutron that is battery operated and wireless connected, so no wiring is needed. Do you start to understand now that your questions can have a myriad of answers, including "it depends"?
Bottom line, if you don't get a pro involved now in designing your wiring scheme, then anywhere you THINK you might have something you want to control, run power and cat6 to that location.
P.S. - I'm not a pro, I didn't sleep at a Holiday Inn last night, but I THINK I've learned a lot from reading this forum over the past 5 years or so. There is a wealth of information at your fingertips here, you just have to search and read.
