Most of these sites have ads. Be aware as you use them that your attention is being exploited by advertisers. It is your choice whether you think the amount of advertising outweighs the usefulness of the information.
Information is the assertion of a fact within a context. For instance, merely to state a number or percentage is not information- there is no context for these bits of data.
Information occurs when you relate them together- for example, The population of New York in 2000 was 8,000,000, an increase of 9% over the year before. The two pieces of data are brought in to relation to one another. That is information.
Propaganda relies on information to be effective, but propaganda will assert and highlight pieces of information out of context and exclude other information which may contradict or throw doubt on an idea. The selective inclusion of certain information will support the point of view the propaganda has been created to serve.
Propaganda is always the work of entities with bias- whether individuals or institutions. The goal of propaganda is to evoke a particular attitude in the reader. Political speeches are often a form of propaganda, since they have as their express goal influencing the thinking of voters. There is a wide array of propagandistic techniques, from outright lies to selective omission of fact.
Many Tweets can be characterized as propaganda, since they are written with the express purpose of swaying public opinion in the absence of documented facts.
Or consider the following from the Republican National Committee Press Release page:
Notice the tendentious tone, and assertion of unsupported facts. Also, overuse of quotation marks, presumably to indicate irony.
Misinformation consists of the passing on of incorrect information without any special bias- similar to misspeaking. Gossip, rumor, and some public figures offer many examples of misinformation without malicious intent.
Presumably President Bush's intent in the remark quoted above was not to reassure the American people that the government would work to increase the number of fatal shootings.
Another form of misinformation are urban legends- although they are passed along as if true, they are never associated with evidence or documentation.
The Snopes website examines and debunks urban legends.
Disinformation consists of lies. It is pernicious because there is nothing obvious about disinformation when you encounter it on the internet or in research- it appears to be like any other source. Scholars have to be vigilant about the source of articles- who is behind the journal, the website, the university? Does the individual or group have a strongly held belief system which might influence their publications? Is there an ovararching goal which all their published work supports?
Don't automatically trust what you find on the internet. If you don't know who wrote it, or can't validate the identity of the author, you have no way of knowing if their information is true.