Digital, it's simple:
- Use a site like iStock for your images
- They present you with all the legal jargon to agree to before you download/purchase each image. You might want to read through it once and keep a copy for your records.
- They provide comps (watermarked and of low quality for obvious reasons)
- Incorporate the price for stock images into your bill for the client.
No more worries -- Digital's works are legit.