The Dest PC Scan 3000 has a SCSI interface.
Install a Dest Controller Card in the PC, connect scanner to that and follow the setup procedure detailed in the manual. It is possible that the scanner will work with other SCSI cards, but I do not know anyone who has attempted this.
There is also an optional Automatic Document Feeder for the scanner, which is fairly common as the scanner was widely used with OCR software for processing piles of documents.
An optional Text Processor card was available for model 3000, and was fitted as standard on the 3020 and 3030. Look for this large card under the glass, near the front of the scanner. It locates underneath a perforated metal cover to the left of the card bearing the 7-segment LED fault indicator.
Dest Text Pac and Dest Recognize. These are primarily for OCR work. They will allow you to scan in text, OCR it, and insert it straight into documents that you are working on, but are designed for use with older wordprocessing software. If your word processing software is not listed, you can still do this, but perhaps with less accuracy.
At least one old version of OmniPage (v2.1) will run the Dest 2000, so you might find a driver for the 3000 in some later version of OmniPage. It seems likely that some other old scanning or OCR software had drivers for the Dest too.