Website keyword research using Google makes a lot of sense. After all, you want to get listed high in Google's rankings don't you? I just typed german shepherd into Google's keyword tool and scrolled down to get the suggestions shown above. Please note that I've only shown a few of the results.
Bearing in mind this part of Google's website is aimed at people who wish to advertise with Google. As can be seen, there are three columns. The first lists the keyword. the second column lists the average monthly search and the third indicates the price an advertiser would probably have to pay to get the phrase listed on the first page of the search results.
Note that the keyword "german shepherd" is listed as having low competition and the suggested cost per click is low. On the other hand the keyword "german shepherd puppies for sale" is listed as high competition and not surprisingly it costs more per click for advertisers to use this.
Bearing in mind that Google does not rate web sites but web pages, this suggests that if your website were all about German Shepherd puppies for sale it might be an idea to have one page optimised for "german shepherd puppies for sale" and another simply "german shepherd" or "german shepherd dogs".
Of course the above is only an example but you do need to find out exactly what keywords are appropriate for your website. Having sorted out the keywords, the next thing is to decide how to use them and that's covered on the next page.