what is acceptable for web site portfolio images

I am putting together a web site portfolio. I have 12 years ID mostly working at companies some consulting. I have disks of images, concepts, photos I took, company glamor photo’s, sketches, presentation rendering ect. Most are concepts that never were produced, some on the market for years, some soon to be. Mostly work quality, not the school protfolio cleaned up or professional glamor shots.

What is legally, ethically OK to post? Should I create slick original, cleaned up work to post? What do most people do? Do you get permission from teh companies for each image? in writing?