There are several tools suitable for online surveys. I have conducted only one online survey so far where I used the free version of survey monkey. It was quite simple to use and perfect for my small survey, where I had about 5 questions and 70 participants. All question types I needed where available, so I was quite pleased with this tool.
However, it is limited in the number of questions and respondents, and one cannot simply export the data. If one aims to have a bigger survey, the free version will not be enough. One possibility is to use Google Forms, where the number of questions and responses is unlimited. The survey responses and data are automatically collected in Google Spreadsheets, which makes it very easy to analyze them.