Open the Citation Databases menu in the lower part of the window, and de-select all but "Science Citation Index Expanded" and (optionally) "Conference Proceedings Citation Index- Science".
Enter your last name and first initial, followed by an asterisk (*) in the Author search box. If you always use a middle initial on your papers, include it as well [jones ab*]. Click Search.
Unless your name is very unique, the results will include papers by other persons with the same name and initials. To increase precision, click the "Institutions" tab under the Refine menu and select any/all institutions that you have been affiliated with. Important: the form of entry of institution names varies. Be sure to view the entire list, sort it alphabetially, and select from that to make sure you get them all. Then click Refine.
Once you have a results list that looks fairly accurate, click on Create Citation Report. The Citation Report ranks the results in descending order of citations received, and provides a year-by-year summary of citations, a sum of Times Cited, an average citations-per-article figure, an option to remove self-citations, and the h-index for this set of articles. Browse the entire report, and mark and remove any entries that don't belong there.
To avoid having to repeat the above process every time you want to see your citations and h-index, you should register for a ResearcherID within Web of Knowledge. This allows you to claim a unique ID number for yourself and then attach it to all your publications. After that, you can get regular updates and reports, and avoid the Author Name problem when you want to repeat this procedure.
Citation metrics are only as reliable as the underlying data. Google Scholar's metrics are generally not reproducible and will differ - sometimes significantly - from data found in Web of Science. Google indexes a different, wider (and largely unknowable) universe of publications. It is difficult to resolve author name ambiguity.
Google Scholar includes a "Cited by" count in its display of individual article entries. This is calculated from citations appearing in other publications indexed in Google Scholar. Clicking on this link will take you to a list of citing articles.
Google Scholar Citations allows you to log in to your Google account and create a personal profile of your publications and calculate citation metrics, similar to the Web of Knowledge ResearcherID system.
An experimental Google Citations Gadget uses Google Scholar data to calculate an h-index for an author name.
Publish or Perish is a software tool that uses Google Scholar data to calculate various metrics.
The h-index is a measure of "citedness" as a surrogate for productivity and impact. It is the number of articles h in a group of publications N that have received h or more citations. For example, an h-index of 20 means that there are 20 items in the selected group N that have received 20 or more citations. It is like a median, and useful because it discounts the disproportionate weight of highly cited and uncited papers that would skew a mean. However, the h-index will vary considerably depending on a person's number of credited publications and the length of time they've been active: older and more prolific authors will usually have higher h-indexes than younger or less prolific authors. If you want to compare your h-index to someone else's, you need to use the same methodology to calculate them and then normalize the values by dividing them by a second factor, e.g. years since PhD. The standard caveats apply when using h-indexes in personnel and funding decisions.