I wouldn't necessarily scrap them - definitely improve them.
You should really just state that it is college work and projects that you worked on.
At this stage you won't be asked to do anything amazing - they just want to see if you have the basics.
If you don't have real work - then that's fine, we were all that soldier.
- My first portfolio is filled with fictional work, as that's all I had, a toothpaste brand (with fully functioning mockup box made from normal paper). I had a poetry book that I asked a local poet could I design the book for him and he agreed, and sent me his poems.
- One of my portfolio pieces was bending a logo around a packaging box, which they were impressed by, it was as simple photoshop technique.
- Another was a textured leaf that I did in Photoshop using a tutorial from Photoshop Magazine.
I still have it - I should post screenshots of it - when I did it first I thought I was brilliant. But looking back - it's a pile of fire kindling. But got me my first job and showed I had the basics.
My portfolio demonstrated I had the knowledge of:
- Booklet making and imposition (as I had a poetry book)
- Keylines and die cutting shapes (toothpaste box)
- Using photoshop to manipulate images and create unique textures
- Illustrator to redraw logos/cartoon characters (I had a Captain America redraw from a comic, picture of comic, plus my redraw beside it)
Definitely book covers are needed - but not traditional novel/plays that publishing houses require. Annual reports, corporate brochures, etc.
Having the book covers would demonstrate your knowledge of how this works, incorporating the spine. But sometimes you have to be careful as there's a score on the front cover sometimes about 5 mm in - and a lot of people don't account for this and have text too tight to it which makes it look awkward.
Having a fictional one in your portfolio is ok - as long as you state it's fictional - it just demonstrates your knowledge and application.
For someone just starting out I'd prefer they have some practical finishing knowledge (how something is folded/printed/laminated/scored etc) than someone who didn't.
But I work exclusively in printing.
If I remember correctly, I split my portfolio into
Illustrator
Photoshop
Quark
And had demonstrations of techniques in each which showed I understood how to make vector graphics, creating keylines and vector manipulation - using photoshop, textures/filters etc. and manipulation - and using Quark for page layout, impositions, and other little things.
This gave my interviewers a clear look at the skills I had learned and understanding of print/design/production.