The Smithsonian often reaches out to the public to help its transcription projects. The most recent is to help transcribe diaries from World War I.
The project is called Operation War Diary, and it comes from a partnership between the National Archives, the citizen science initiative Zooniverse and the Imperial War Museum in the UK. The diaries have all been scanned and posted online for citizen historians to look at and transcribe.
To participate, users just pick a diary and get started. They’re then given a scanned page to classify and document. Users are asked to take notes of particular data points—the date of the entry, whether the entry lists casualties, what people it mentions, if it has a map and more.
Currently, these documents are only available in paper form. However, the Smithsonian hopes to change that by making them fully digitized! To volunteer for this important project, please see their blog post here.