Your DSLR can do it in about 5 seconds each.

You need a tripod, a piece of glass and a decent light.

Try to come up with a way to work at table height. Aim the camera straight down.

Put a flat board down, and make a right angle of masking tape. You can apply the tape directly to the table if you are absolutely sure it won't pull off the finish. Not a problem on formica. May be a problem on wood tables.

First: Use a sheet of graph paper. Adjust camera position until graph paper is perfectly at right angles. If you have distortion, use another lens. For this use a prime between 60 and 120 mm works well for a crop sensor, 85 to 200 for a full frame.

Set camera to manual focus. Put a couple rubber bands on your lens to avoid focus creep.

You may want to do this tethered to a laptop to catch problems early.

White balance: I think you are better off setting white balance to manual and match it to your light source. This may not be perfect but all of the images will be off the same way.

The light should shine on the glass at a 45 degree angle. You can use off camera flash for this. I find it distracting. I use an Apurture LED light. Good white balance for this. If you use incandescent bulbs, go for halogens.

You need a piece of plate glass (no density striations) larger than the picture. Tape one edge down, and tape a handle onto it so you can easily lift the edge to change pictures.

The ceiling above you should be dark so there are no reflections of the ceiling from the glass. If you have a light coloured ceiling a chunk of black posterboard and 4 thumbtacks may rescue you.

Sometimes just working at night with the downward facing copy lamp is enough. You can check for reflections by putting something black under the glass.

Take a few shots with a photo under the glass. Transfer to computer and check them. Hold the photo at the same time. If the colours look really wonky, try a different light source.

Workflow

If you have an interval timer function on your camera set it to about 10 seconds.

Action:

Take a packet of pictures. If you can find a date on the packet write the date on a piece of paper, and put it under the glass. Write the same date on the packet. I like using a sharpie for this, as it is easy to read in the pics.

Remove pix from packet. Take top picture put under glass. Wait for click. While you are waiting, get the next one ready.

Swap pix. Pic you just shot up goes face down, starting a stack. This does two things:

A: You know which stack is next and which is done.

B: When you've done the packet, the pix are in the same order.

Repeat for each packet. Don't fret if the camera takes a few blanks while you are fussing with the next packet.

The date on the packet says you've processed that packet.

Once you have done a packet or two, process that batch. This is where you find bugs in the system.

Albums.

May as well slow down the camera. It will take time to remove a shot from an album, and replace them. Look at the back of a few pix. Sometimes the date development date is on the back -- usually just month year. If you can date an album, write the date neatly somewhere -- inside the cover, on the spine. You can get fancy and put it on a label. You can name an album too if it's themed. Like before first shot is a piece of paper with the identifier for the album.

Generally people transfer pix from packets to albums as a unit, but the packets may not be in date order. You may or may not care. If you care, as you remove them, look at the back. If it's dated, you can write the date on another piece of paper and put it down with the Album piece of paper and snap that. Knowing the album that a shot is from helps if you need to find it again.

Boxes.

These are the worst. Pix are often just loose. They may have been gone through a few times. If boxes were open, there is a lot of dust to deal with.

Dealing with dust: Take a fan, and tape a furnace filter to one side. The frameless furnace filters work best for this. A box fan is easiest. By dusting prints next to the fan, you don't end up with a cloud of dust everywhere. You can use a vacuum for this, but it's noisy.

Buy a new soft bristle paint brush for dusting. Natural bristles don't have as much problem with static. A 2" brush intended for oil based enamel works well. Paint stores have better brush selections than the Orange Box.

A swiffer duster may work.

Back to the boxes: If there are clumps, take the whole clump. Spread clumps out over the table. Individuals become their own clump. Pick up a clump, and check for date stamp. If stamped, write a date label (same one you will use later, lay it beside the clump. Check each pic in the clump to see if it is the same date. Repeat this for each clump.

Either after or while you are doing this, put the stacks in date order. Once you have done clumps, do the individuals and see if they have dates that match up to the clumps. If so add them to the clump stack. If not, start a new clump.

You may end up with multiple clumps with the same date. Likely from a holiday, or someone with a new camera.

You may want to spread out each development date and see if they are in reasonable order. Group similar shots. This is also time for some facetime consulting with your sibs. You can use your cell to send representitive shots. "Did we do the tower of London before or after Kew gardens."

If you want to keep the originals, get albums or get acid free envelopes. Do Not use Kraft paper (brown; manilla) You can go whole hog and get archival envelopes, but that's likely overkill. A good quality white envelope is likely good enough. Uline is probably the cheapest source for envelopes. Write the date on the envelope.

Complications:

My grandfather would write notes on the back of the picture. This is valuable metadata. So if there is writing on the back, do that side FIRST. When you do the next pic, that the present one is upside down reminds you to flip it over. If it was right side up, like most of them, and you are interrupted, you may not remember to do the back.

Edit:

From a comment: Shooting tethered or with a remote, allows you to work at your own pace. As would hitting the shutter release. The former methods avoid camera shake from you touching the camera. If you use a remote, I would tape it down so that you don't have to pick it up each time.

Why not use a scanner?

I have an Epson v700 scanner. It takes an inordinate amount of time per scan, and does so in 3 passes. It takes about a minute per scan for 8x10s I'm sure there are better scanners out there.

The reviews I've read on photo scanners show poor dynamic range, and with many of them an unacceptable increase in contrast. Read reviews carefully. Be sure you can return it. I would suggest not bothering with anything not specifically sold for scanning photos.