ResearchScreen
The research screen is where you go to research new technologies.
There are several areas of interest on the research screen:
At the top of the screen there is a display which shows how many research points you have to spend this turn. Unspent points are automatically assigned to a random technology, so you probably want to spend all your points each turn! There is also a selector to filter the list of technologies by category, and information on the currently selected technology.
On the left is a list of technologies that you can research. Double-click one to add it to your research queue, or click it once and set the slider on the right to allocate a portion of your research each turn to it. (It's recommended to use the queue unless you are playing a mod which has a random research breakthrough script.)
On the right is a list of expected results from the selected technology. You can right click on one of these to open the tech tree browser.
Below the expected results is a button to add the selected technology to the queue (same as double clicking it), and a list of queued techs along with the ETA for them to be completed. Below the queue are buttons to reorder the queue and remove items.
In the lower right there are buttons to save your changes, cancel, and view the entire tech tree in the tech tree browser.