The Research Methodology Ebook Collection provides 24/7 access to texts covering a variety of research methodologies for beginning and advanced researchers. Online works for each methodology are listed under the relevant tabs.
SAGE Research Methods is the ultimate methods library with more than 1000 books, reference works, and journal articles by world-leading academics from across the social sciences, including the largest collection of qualitative methods books available online from any scholarly publisher. The site is designed to guide users to the content they need to learn a little or a lot about their method. The Methods Map can help those less familiar with research methods to find the best technique to use in their research.
Research Design: quantitative, qualitative, mixed methods, arts-based, and community-based participatory research approaches
The SAGE Handbook of Social Media Research Methods by 
