You can search for journal articles in Google Scholar and use the "Find it @ Oxford" link to access electronic versions. Scholar is the largest database of scholarly literature and gives you quick, relevant results but it lacks search tools and gives too many results sometimes.
For more structured literature searching you might try World Wide Political Science Abstracts which has been the standard in political science bibliography for many years, or Web of Science which uses citations for relevance and article ranking.
JSTOR contains the full-text of many of the classic international politics journals back to their earliest issues.
The International Bibliography of the Social Sciences (IBSS) also indexes political science content and includes more non-English language material than the other databases.
If you want to be alerted about new journal issues and tables of contents then sign up for the Zetoc service (see quick guide on this page).
Find more databases for political science research on OXLIP+
Here are some tips to get the best out of Google Scholar:
Citation searching (finding out what articles have cited an article or book after publication) can be done on Web of Science (Social Sciences Citation Index) or for articles published after 1996 on SCOPUS.
Google Scholar also has 'cited by' links but these are not yet fully reliable.
To find articles and books cited within books try searching Google Books with the reference in quotation marks.
To use Zetoc Alert and RSS feed you must use your Oxford Single Sign-on