Sometimes you end up with an unmanagebly large list of papers, and this is often results from a very general search.
Tips
Try a subject specific database
By choosing the right subject specific database (determined by your topic) you will naturally be only viewing articles in that subject area, and therefore focusing your search.
Avoid very general databases such as Academic Search Complete or the OneSearch feature on our homepage. Those cover so many subjects your search won't be focused, and you'll likely have far too many results to feasibly review.
Try more specific keywords
Brainstorm or talk to someone to think up some
Try using additional keywords
Two to three keywords is great. Just one is too broad of a search and more than three is often too specific
Try using this diagram to brainstorm keywords
Limit by document type
The databases you'll be searching in will have journal articles and also other kinds of publications, including book chapters and conference papers, and others. Frequently you'll just be looking for journal articles, and this is a very common limiter or filter in literature databases. It might not trim the list down dramatically, but just go ahead and do this if that's all you are looking for.
Limit by language
This might not trim down the list dramatically either, but you can easily limit your results to only those in languages you can read. This is also a very common limiter option in literature databases.
When appropriate, limit by date.
Be careful with this one, as it's not always a good idea - you can miss great papers by doing this. However if you have an over abundance of results or a time sensitive topic (either for very recent or rather historical), this might be a good choice.