How to plan a sightseeing trip in US?

How do you plan a sight seeing trip in US? What is the process involved? What are some useful websites to gather information regarding your travel, places to see, hotels to stay, etc., How to get the best deals when booking car, hotel, flights etc.,? Where can you get some useful feedback from 'real people' (as opposed to just marketing blurb)? You'll find answers to all such  questions in this post.

What qualifies me to write this post?! Well, I've visited 32 different states in US and have made at least 15 sight seeing trips in a row with my family (which includes a toddler). I'm more than excited to share the art of planning for a trip, with all of you. (Disclaimer: The more trips you've made in US, the less useful this post will be to you.)
 
In the best interest of my readers' time & to improve the readability of the post, I've decided to make it as a multi-part writeup. The first part will talk about 'Selecting the Destination and Places to See'.

The first thing you should decide when planning a trip, is your travel destination - "Where do you want to go? Do you want your vacation to be relaxing or tightly packed? Are you interested in doing a lot of activities or do you just want to do sight seeing? Do you want to drive to a destination or do you want to fly? Lots of these factors go in, during the decision making process. Also, it depends on your family members, their health/fitness conditions, your interests, etc.,

Once you have identified a set of destinations for your trip, the next thing you have to find out is "Is this a right time to go there?" For example, you should visit places like New Hampshire in Fall, Portland during Spring, & Glen Canyon or Crater Lake during summer. Your timing of the trip is very important and it influences your travel destination.

The third big question is "Will the trip or destination fit my budget?". If you have budgeted just $200, all you can do is a simple road trip to a nearby place. At the same time, if you have $2000 or more, you can do a fun-filled trip to Hawaii or you can take a cruise. So, your budget for the trip is very important in deciding the "destination".

The fourth question that you should ask is "How many days do I want the trip to be?". The number of days of your trip is dependant on your work schedule, the destination, your family members, your budget etc., Most of my trips were about 3 - 5 days long and it worked out well for me.

After finalizing your destination, you have to identify the list of places to see in/around that destination. You need to do a lot of research for this. Here are some tips:

1. Look at Trip Advisor. This website gives lot of useful tips regarding 'places to see' with real user reviews.  
2. Visit About.com. They have lots of interesting articles about special destinations (such as New York, Hawaii, etc.,) 
3. Visit US National Park Service website. This website provides useful information regarding all National Parks in US, monuments & historical sites 
4. Search Wikipedia. Wikipedia gives information regarding the destination, culture, people, important land marks, etc.,
5. Look at State/City web sites (or Chamber of Commerce websites). Each state/city in US maintains a web site and those websites have tourist/visitors section listing the 'sight seeing places'. For example, this is the website for the City of Idaho Falls and there is a link for visitors.     
6. Search through Yahoo Answers. Yahoo Answers has a travel section and there are so many active participants there. You can get lots of useful tips, suggestions and help from the folks, there
7. Look at the List of Places to See in USA article 
8. Do Google Search. A simple "places to see in " would show thousands of entries. Of course, you need to read 100s of articles to gather information
9. Search Google Maps. Google Maps also provide some information regarding the attractions near to a place/locality. Just type "attractions near " in the search box. You'll see lots of results. 
10. All modern day GPS devices provide travel details regarding nearby attractions, museums, historical sites, etc.,. They make your trip planning very easy. If you have postponed the job of 'selecting the places to see' till the day of your trip, just buy or rent a GPS. You are all set for the trip. In fact, GPS helped me very much during our road trip. Otherwise, we would've got stranded.

Hopefully, this post gives you enough tips to select your travel destination and the list of places to see in each of those destinations. The next post in this series will give you tips regarding How to get the best deals for airline, car, and hotel booking?.