From what you describe as your intended uses, the TIFF specs are creating very large, high resolution image files that are probably way bigger than you need. The very large files will be useful only for making 8x10 or larger prints. You will need to resize these files to email them or use in them in other documents as inserts, etc.
There are any number of freeware products that will load your large TIFFs and resize/save as JPEGs. I and others have used FrastStone Image Viewer for years. You can resize/resave one image at a time or batch process as many files as you want. You can test out what you need by resizing/resaving one image, print out, etc. For most people's regular use, JPEGs will be fine. If you plan on seriously archiving your photos, then the larger TIFFs are great, but as you have discovered you will need to copy/back them up to an external harddrive or burn DVDs for long-term storage.
am new to all of this and I realize I am starting from the middle instead of the beginning, but I need some basic help please. I have just scanned over 1500 slides using and Epson Perfection V700 scanner. I surfed the web for some advice on settings and decided to use the tiff format, 48 bit color and 3200 dpi. They look great on the monitor, but I still have about 500 to go and have run out of space on my computer, even with 218 gb of space orignially. What do I do now? Even if I purchase another hard drive they will still be in only one place and I planned to have them in at least two separate places to ensure safety (some of the slides are getting moldy so even keeping the originals are problematic). Should I convert them all to jpeg? If so, how would you recommend I do this? Is there some software that would make this job easier? I have access to photoshop elements and photoshop 7.0 but my skills are limited. My ultimate plans for these slides are preservation, a few family dvd's, a few in emails, some prints, no larger than 8x10 and most 4x6. Any assistance would be greatly appreciated.