Sometimes they have to be included after the main text.
The most used standards for referencing in research papers are APA-standard and MLA-standard.
Some paper formats allow you to include footnotes in the text, while some do not allow footnotes.
If you do not know what to write about, you will have to look for ideas for research paper topics. An empiric paper frequently follows this structure: When correcting papers, we have been surprised by the many students struggling with intext citations.
The structure of a research paper might seem quite stiff, but it serves a purpose: It will help find information you are looking for easily and also help structure your thoughts and communication. Although the standards are somewhat different, citations in the text should not be too difficult to master.
Scientific journals use peer review process, which is a panel of other researchers (most likely in the same field) who review the work, to ensure that the quality of the paper.
Publication bias is a well known phenomenon, as the peer review process often rejects "null results".
You will need to revisit each subtopic to insert your own analysis and arrange the proper order of your paragraphs in the final stages.
Be sure to cite all information that is not common knowledge.
Pick five interesting aspects that could serve as subtopics of your subject.
Focus in on a few major points that you could write about. Read or skim those to find the most relevant and useful information. Be careful to indicate your source name and the page number for all information you record.