Every local history group reaches the same moment. A box file of photographs, a memory stick from a former secretary, a shoebox of postcards and a scanner borrowed from a member's son. The enthusiasm is there. What is missing is a system — something simple enough that a volunteer can pick it up on a Tuesday evening and still be useful in ten years' time.

A digital archive does not need expensive software or a specialist. It needs a spreadsheet, a naming rule and a clear note about who is allowed to see what. Get those three things right and the rest follows.

Start by taking stock

Before you digitise a single item, spend two evenings working out what the group actually holds. Not everything is worth scanning. A blurry photograph of an unidentifiable street corner takes up the same storage as a sharp 1950s wedding portrait, but only one of them will be requested by a researcher.

List the collections: photographs, documents, maps, oral history recordings, objects, newsletters, minutes. For each, note roughly how many items there are, where they are physically stored, and who looks after them. This inventory is the foundation, and it will change what you do next. Groups often discover that their most-requested material is not what they assumed.

The spreadsheet is the archive

The digital files are just files. The spreadsheet is what makes them findable, and it is the single most valuable thing your group will create. Use any spreadsheet program you like — the format matters far less than the consistency.

One row per item, one column per fact. A workable set of headings looks like this:

• Accession number — a unique reference, never reused, never changed
• Title — a short description written for someone who has never seen the item
• Date — use what you know; "circa 1953" is a legitimate entry
• Format — photograph, postcard, typescript, audio cassette, map
• Physical location — which cupboard, which box, which shelf
• Digital file name — exactly as it appears on the drive
• Date digitised and digitised by
• Copyright status — known, unknown, cleared, orphan work
• Donor or source
• Notes — condition, related items, anything a future volunteer should know

Freeze the top row, apply a filter, and you have a searchable catalogue that will outperform most home-made databases. Back it up somewhere other than the laptop it lives on.

File names that a stranger can read

Digital files get separated from their folders. A name like IMG_4471.jpg tells a future volunteer nothing. A name that carries the accession number and a short description will always find its way home.

Agree one pattern and write it down. Something like ABCD-1953-0147-Bridge-Street-school-class works well: group initials, year, accession number, then a few words. Use hyphens rather than spaces, avoid punctuation marks that confuse different operating systems, and keep dates in the order year-month-day so they sort correctly.

When you have several views of the same item, add a letter at the end — -a, -b, -c. Never overwrite an original scan with an edited version. Keep the master file untouched and work on a copy.

Scanning and storing without losing quality

For photographs and documents, scan at 300 dots per inch as a minimum, and 600 for small prints, slides or anything with fine handwriting. Save the master as a TIFF, which does not lose quality each time it is opened. Create a smaller JPEG as an access copy for sharing on the website or in talks.

Audio needs the same discipline. Convert cassette and reel recordings to uncompressed WAV files before making MP3 versions for listening. Store masters in one folder, access copies in another, and never let the two get mixed up.

Follow the 3-2-1 rule: three copies of everything, on two different types of storage, with one copy held off-site. An external hard drive in the treasurer's house, a second drive kept elsewhere, and a cloud account with a reputable provider will cover most groups. Check the drives every year and replace them every five. Storage fails quietly; a calendar reminder is cheaper than a lost collection.

Permissions, copyright and courtesy

Digitising an item does not give you the right to publish it. Copyright in a photograph usually belongs to the photographer or their estate, and it lasts for seventy years after the creator's death. Written permission from the donor, on a simple form, is your protection — and it should state clearly what the group may do with the material.

For oral history recordings, the interviewee must sign a consent form covering how the recording may be used. Material about living people is also personal data under UK law, so restrict anything sensitive to an internal folder and publish only what is appropriate.

Set out three levels of access and apply them consistently:

• Public — cleared for the website, exhibitions and social media
• Group only — usable in members' research but not published
• Restricted — closed for a set period, or until permission is obtained

Record the level in the spreadsheet and review it every couple of years. Circumstances change, and a restriction that made sense in 2015 may be unnecessary now.

Making it last beyond the current committee

Write a short handbook — two or three pages is enough — covering the spreadsheet columns, the naming rule, where the files live and who holds the passwords. Keep a copy with the group's records and give it to every new volunteer on their first session.

Then appoint two people, not one, to look after the archive. Shared responsibility survives holidays, illness and the quiet departure of a long-standing member. Review the whole collection once a year: check the backups, close out unfinished rows, and celebrate what has been added. A digital archive is not a project with an end date. It is a habit, and a generous one — the small, careful work of making sure your town's history is still here for whoever comes looking next.