World Wide Science is an online portal that lets you search millions of academic papers and journal articles that cover subjects such as IT, medicine, physics, chemistry and lots more. If you want in-depth knowledge about a particular topic, this is the place to find it.
Although not all referenced articles are freely downloadable as full text (sometimes you have to pay if you want to read anything except the summary), there are still loads of full articles to read. The availability of a full downloadable copy is clearly indicated in the search results.
So to broaden your knowledge, head to www.worldwidescience.org and get searching.
Comments
In addition to the local and state libraries many colleges also provide excellent information online related to a variety of scientific disiplines. If you have an interest in genetics the University of Utah has a nice offering here >>> http://learn.genetics.utah.edu/
Nice share -- thank you
Sciencedirect has been one of my bookmarks for some time and I agree that it provides some excellent information. The website Rob has mentioned looked like a promising addition until I clicked on the home page news heading and saw the most recent entry was August of last year.