A combination bookmarking, note-taking, and web clippings tool, diigo is particularly well-suited to organizing your research. It allows you to bookmark pages, highlight text on them, write notes about them, and add sticky notes to them - all in one place. Once you've added items to your diigo account, you can organize them into lists related to a certain project. Here is an example of a diigo list related to Polish resettlement.
If you're a visual learner, you can even view your list of resources as a slideshow using the WebSlides widget(click onthe play WebSlides icon beside the list title near the top of the page). As an added time-saver, you can set up your diigo account to add items to your delicious account (or several other bookmarking tools) simultaneously - including your tags and notes.
Check out this YouTube video for a 5-minute introduction to diigo and social annotation.