Trip to Peru

I can't comment on Peru, but I would highly recommend using the Footprint guide. I used it for a former DYI trip in northwest Argentina and it was very helpful. Peru has a lot written about it so it shouldn't be too hard to find lots of resources even in the local library, and to see where various tour companies are taking people to get a better feel of timing and itineraries (if this is a DYI trip). Look into Southern Explorations for trip ideas - I plan on using them to see Ecuador.
www.southernexplorations.com/

All of our travel to date has been DYI. Peru seems more intimidating logistically, so I would be open to a travel company. Generally, we prefer the flexibility of independent travel.

I went with a group of friends to Peru and Ecuador ( 1 week each place)
We used Gate 1 Travel and found an excellent price, fantastic guides, really nice hotels - inter country flights for some of the longer trip segments.
We flew out of LAX on LAN Air to Lima
We saw all the sights you mentioned, but did not take the optional to Nasca.
We then flew to Ecuador and started in Quito and traveled many different places in Ecuador and even took a canoe into the Amazon and stayed 2 nights in a lovely resort hotel.
You might go to Gate 1 Travel site and look to see where they take their travelers and in which order to help you plan your trip a bit more.
Happy Travels.

Thanks for the suggestion. Did you feel like 7 days in Peru was enough to get a good overview of the highlights?

I don't think you will be able to cover all the places you originally listed in 7 days especially if you are doing it on your own.

For Peru in general, I'd recommend Lonely Planet's Peru. For Machu Picchu, I used the Machu Picchu Guide by Ruth Wright which gives you all the information to explore on your own.

When doing Machu Picchu, you will need to decide if you are going to do this as a day trip from Cuzco or follow the backpacker route and spend the night (or 2) in Aguas Calientes at the bottom of the hill. The latter is recommended if you want to spend the whole day and will give you a chance to climb Huayna Picchu too. This way you can watch the sunrise over the ruins. I believe if you try the day trip from Cuzco, you will be limited to about 4 hours at the ruins before having to catch the bus/train back to Cuzco.

If doing lake Titicaca, you will probably need to spend two nights in Puno.

Similarly, if you plan to go to Colca canyon, you will probably need 3 nights - Arequipa - a village close to the canyon, and another night in Arequipa.

The amazon will probably be tough to pull off if you only have 7-8 days but probably easy if you are planning on spending 2 weeks in Peru.

Its been quite a few years since I have been to Peru so my info is not the most up to date, but we loved lake Titicaca - spent the night out on taqile island which was awesome. Colca Canyon was nice.
As for guides we used Lonely planet in conjunction with some organized your parts.
We spent a few days in Cusco either side of doing the Inca trail and loved it. I think it is a lot more commercial than when we were there in the mid 90's, but It is still my favourite country that I have visited (yes, better than france, England, Italy etc)
Have a great time.

the highlight of peru for me is cuzco/mp, lake Titicaca (spending a night on the floating island with an indian famiy), colca canyon/Arequipa, and the rainforest. I only had about 3 weeks so I didn't make it to nasca. you can get any book to plan the trip, it's very easy to do it on your own. I bought all of my flight tickets and bus tickets online before I landed, except the train tickets and park fee to enter MP - there are so many tour operators in cuzco around plaza de amas you can shop. i'm very impressed with their tour guides and agencies - didn't expect them to be that good! even the bus rides were fantastic - the views on the buses are great, I saw a lot of wild animals and birds, the mountain and sky are so beautiful, it's a great place i'd go any day.

Thanks for the feedback. I feel like I have a good handle on the highlights now. Now I just have to decide if I want to try a tour or DYI. I think I'm leaning to some combination of doing stuff ourselves and just going with local guides at each destination to get to the sites once we're there.