After submitting your paper to a conference, instead of being invited to make a ten-minute presentation, you may be invited to present a poster instead. This is a good opportunity to put your work in front of others, and it should involve different techniques to those involved in making a presentation.
The first thing about posters is that your message about the research you are doing is more important than any corporate or brand image of your institution. I would avoid the habit of cluttering up your valuable piece of paper with logos, names of research units, collaborators and so on. You may find that there are certain requirements of some funding agencies and some institutions to have a clear acknowledgement of their support. These should be adhered to. But don't add unnecessary logos and associated names unless they are really needed.
Next, it is good to use graphics and large fonts. A good poster will focus on one aspect of your work, rather than trying to put everything across. There is no need for bibliographical references, and it is good to avoid jargon and complex sentences; big fonts, nice graphics and short messages. Graphical communication works best when you avoid fussy and unnecessary embellishments such as 3D, shadows, gratuitous use of colour and so on (most of the default settings in Microsoft Power-point and the like need to be changed to remove many of these features; it was developed for business presentations, not research presentations). An overriding principle is that the density of data in a graphic should be greater than the equivalent text that might alternatively be used to represent the same data. So pie charts are a complete waste of paper, because the message in a pie chart can be put across in one sentence of text. Histograms are frequently better portrayed as a list of labels and numbers. Your audience is not innumerate, and they understand the relative sizes of numbers. (You don’t need to draw me a picture to explain that 75 is much bigger than 10.) Graphics work best when every line, colour, symbol and label perform a function that is more concise than writing things out. There is some really good advice and detailed exposition on the use of graphics for conveying information by Edward Tufte; get hold of it if you can.
It is interesting to type “scientific posters” into Google. That is how I stumbled upon some useful guidance from North Carolina State University where it is emphasized that there are basic principles of scientific poster design: Focus, Graphics, Order. I like the advice given there. Also, I recommend a good PhD Blog, called the Thesis Whisperer, where there is further good advice.
To summarize, this is a good opportunity to develop a skill-set that differs from making presentations. Posters should have minimal clutter. There should be a clear focus, good use of graphics and a clear sequence of ideas. This will make it easier for observers to ask questions and for you talk about your research. Finally, it is OK to be uncertain about research that is in progress.