Ok, rethought for better or worse...I have been through this and went through the same processes of wondering what to do. Finally got a family photo book printed (through Aperture) and it is great.
The problem is that you have found yourself to be responsible for saving all your family history and this is going to be expensive and time-consuming. Since your work may go down to many following generations, you want it to be good and not have your great-great-great grandchildren cursing you for sloppy work!
1. You have thousands of slides in 35mm and 110?
It is essential to go through them and brutally throw out the bad ones. Remember, future generations do not want to see 500 photos of Aunt Mary. A few that show her essence, a depiction of her life, is right. More photos than that and their eyes will glaze over.
2. Send out the keepers to ScanCafe or whoever. It is not worth scanning small format yourself!!!! I went for the high quality scan, but not the dust removal, etc. as you have to do so much correction on your computer anyway.
3. Every slide scan you keep to publish will need work. Aperture, Lightroom, Elements, etc are enough. You do not need Photoshop for this unless you are going well beyond normal restoration. I happen to have Aperture and it can do what photos need: cropping, straightening, retouching, saturation, color correction, sharpening, contrast...and the clone option works to remove creases, fix up borders and replace deteriorating. It also keeps a master photo in case you simply need to start over.
One nice thing about Aperture is that it preserves the original, so even if you make a mistake you can go back.
4. If you do have hundreds of 120 film/negatives, that is a problem financially. It will cost hundreds or thousands to send them out. These 120 or larger negatives/slides can be done on a quality flatbed. Bear in mind that nothing less than a V700 will do for slides and negatives! Don't think anything else will work well at all.
It is math at this point. If you have enough scans to do, then maybe find a used one and then resell it.
Just understand that you really need to send out 35, but you can do 120 at home. Cheapo 35mm scanners...no.
If you also have prints to scan, then the V500s and the like are great at reflective scanning and serve your general non-photo scanning needs as well.
Bear in mind that you cannot always make a bad photo perfect at all, just simply as good as it can be. As you do this, you get better at it and at making decisions about what is worth doing. Of course you will come across a few priceless old photos that you work on for hours because they are worth it.
As an end note, you will probably find that the really old photos, taken prior to the days of 35mm, are better. Photography was the mostly the avocation of professionals and dedicated amateurs. Each photo cost money, sometimes a lot of money, and they did not take 500 photos of a dog laying on its back. Almost all of the really old photos are keepers whereas only a small percentage of the small format photos are. And digital...probably a .05% keeper rate overall.