I'm doing a research report on the Stonehenge. Would a good thesis be that building Stonehenge took a lot of hard work, and that its construction took a lot of planning? This is not my actual thesis statement, but would this be a good idea to prove?

That is not a thesis statement because no one would dispute you about any of that.

A thesis statement must include factual information (which you already have) plus your position/opinion/stance. Without your position on the topic, it isn't a true thesis statement. So think of this sentence as the angle you want to take on the topic and what you intend to prove by the end of your paper. (If your statement is simply factual, then there's nothing to prove!)

http://leo.stcloudstate.edu/acadwrite/thesistatement.html
This is one of the very best places I've seen online to help students write good thesis statements. It shows you sentences that aren't thesis statements and how to turn each one into real thesis statements.

Here's a really good website to get help researching and writing a paper:

http://www.ipl.org/div/aplus/

Click on Step by Step (toward the right) and follow their directions.

Yes, your idea of focusing on the hard work and planning involved in building Stonehenge can make for a strong thesis statement. To further develop and prove this thesis, you can consider the following steps:

1. Research Stonehenge: Gather information about the different aspects of Stonehenge, such as its construction timeline, the types of stones used, the engineering techniques employed, and any archaeological evidence related to its planning.

2. Identify construction challenges: Explore the challenges that ancient builders would have faced during the construction of Stonehenge. This can include problems like transporting the massive stones, shaping and fitting them together, and assembling the entire structure.

3. Study the workforce: Examine the labor force required for the project. Investigate the theories surrounding the builders of Stonehenge, such as whether it was undertaken by a well-organized group of skilled craftsmen, a large community effort, or both.

4. Analyze planning and engineering techniques: Determine how much planning and organization were necessary for the project. Investigate the alignment of the stones, their positioning in relation to astronomical events, and other evidence that suggests careful planning and engineering skill were employed.

5. Consider the importance of Stonehenge: Explore why Stonehenge was built in the first place. Investigate theories surrounding its function and purpose, such as religious or ceremonial significance, astronomical observatory, or a symbol of power and unity.

6. Support with evidence: Collect concrete evidence from reputable sources, such as archaeological findings, historical accounts, scientific studies, and expert opinions, to support your thesis. Use these pieces of evidence to reinforce your argument about the hard work and planning involved in the construction of Stonehenge.

By following these steps and backing up your thesis with substantial evidence, you can create a well-supported research report on Stonehenge that explores the hard work and planning required for its construction.