To create a professional-looking design use a specialist graphic design application (known as Desktop Publishing software) for your charity's publication, rather than a word-processing application such as Microsoft Word.
Microsoft Publisher, which comes bundled with certain versions of Microsoft Office, is easy to use and is good for basic design work.
However, Publisher doesn't offer as many features as other software and many printing companies don't accept Microsoft Publisher files. Instead, you may be stuck giving them a JPEG of your design.
JPEGs aren't a good format for commercial printing as they lose information. This particularly affects text at small font sizes - the text will be printed with slightly fuzzy edges.
If you are able to invest money and time, it's worth purchasing one of the more complex and expensive Desktop Publishing applications such as Adobe Indesign or Quark XPress. However, these applications are expensive with a RRP over £700, and are harder to learn than Microsoft Publisher.