Going abroad is not a joke and hence requires lots of preparation and mind make up. If you are just starting to think about abroad then the links I will be providing here may be of great use. So lets start!
http://ets.org : ETS stands for English Testing System. As most of the universities in Europe and United States require either TOEFL or IELTS for Masters, this site is a must to visit site as its a site for TOEFL, plus its official site to get information about GRE as well. Get PowerPrep software from the site to get started with GRE. Believe me its the first software or ebook which you should read before thinking about any other ebook or even institutes and consulants. Though the software has a bit old and boring interface but its official software and source of information. To download that software (about 11Mb), you must create a free account in that site.