Formats more likely to be accessible in the future are:

• Non-proprietary
• Open, documented standard
• Common usage by research community
• Standard representation (ASCII, Unicode)
• Unencrypted
• Uncompressed

Consider migrating your data into a format with the above characteristics, in addition to keeping a copy in the original software format.

Examples of preferred format choices:

• PDF/A, not Word
• ASCII, not Excel
• MPEG-4, not Quicktime
• TIFF or JPEG2000, not GIF or JPG

Library of Congress' recommended file formats.

Simmon's College guide.

NYU's guide. 

MIT's guide.

Directory structure naming 

When organizing files, directory top-level folder should include the project title, unique identifier, and date (year). The substructure should have a clear, documented naming convention; for example, each run of an experiment, each version of a dataset, and/or each person in the group.

File naming

• Reserve the 3-letter file extension for application-specific codes, for example, formats like .wrl, .mov, and .tif.
• Identify the activity or project in the file name

Use free tools to help you:

http://www.bulkrenameutility.co.uk

http://renamer4mac.com

http://www.powersurgepub.com/products/psrenamer.html

File naming conventions for specific disciplines

DOE's Atmospheric Radiation Measurement (ARM) program