You can find it by using google's external keyword tool. https://adwords.google.com/select/KeywordToolExternal
Well, The above tool suggested by michalka would not give you idea about keywords competition. This is misconception to most of the people or may be for the new SEO. Finding keyword competition needs lots of research and consideration of many factors however since you sound new you can try below method: Go to google.com and write intitle:"your keyword", note down no. of results came out of this query and this is the competition for your keyword in general.
If you want to know about competition of keywords, go to google adword keyword tool. Type the keyword which you want know about the competition. You will get list of keyword with search volume. There you can see the search volume of your keyword. That is the competition of your keyword.
Keep in mind that the google adword keyword tool shows competition for adwords and not for SEO. You can simply type your keyword into the search field of google. When you get your results, you should see "about xxx,xxxx results." those are your competing pages. Using intitle:"keyword" or using inurl:"keyword" will show you exactly how many competing pages have that exact keyword on the page title or in the page url. If you are using long tail keywords, typing [keyword keyword] in google search will show you all the competing pages that have those exact keywords on their page. This is also helpful to know because if you have 200,000 competing pages with regular search but only 5000 competing pages using exact search, there's a good chance you can rank high for that keyword. The reason is, in google's eyes, your site is more relevant for that keyword than the other pages that do not have an exact match. Other factors like PageRank and number of backlinks come into play as well when you are looking at the top 10 results. You can install a browser plug-in like SEO quake to help you get information like that.
if you're ready to pay some bucks, then go ahead any buy Market Samurai. It is one of the best keyword research tools out there in the market.
my method is very simple type your keyword in google search engine and copy 1st website of the result and past in backlinkwatch dot com and u will come to know the competition of backlinks of the keyword.
Yea, Its free & powered by the almighty Google why think about other alternatives when the big G is offering something for the same?
Analyze the keywords in Google Adwords Keyword tool. It will help you to know more about the local & Global monthly searches which helps to know more about the competition of the keywords
I agree with Becker09, you will not just want to know the competion for one keyword or one competitor but over time more an dmore, whereas you can manually do all of this it takes a long time to get it right. Try Market Samurai it is a great tool and you can get a thirty day free trial.
Google's keyword tool is the one I always use. It will show you the amount of global and local searches for your keywords plus an indicator of how much competition there is for that word/ phrase. The Inurl search other posters have mentioned isn't that useful because you get no context with the result.
Whereas I agree that Google Keyword tool is a good starting point you must be aware that the competion box shown is the number of competitors in ADWORDS which is what the tool is about.
For finding the competi0on of a keyword just enter your keyword in Google and the value which you will get in "about xxx,xxx" is the competition of that keyword.
Go to google and type in your keyword. It wouldn't matter how many numbers of competition is there. The only competition is the top 10 results of Search Engine Results. If you don't have much money to invest in tools. Try downloading SEO Quake to analyze the top 10 results and see how many backlinks, age of domain and other seo factors involved in getting number 1 for that keyword.