If you're homeschooling preschool through 3rd grade or so, or are looking for summer projects or worksheets, check out enchantedlearning.com . I use it for printable worksheets for every subject from phonics, to math, to geography, to art, and a few others. You can print many pages for free without a membership. I recommend the membership if you see you'll use it a lot. With the $20/year fee, you get access to the entire website, pages that are more printer-friendly, and a banner-free version of the website.
It's great for my Kindergartener and I, because we use workbooks I've picked up from the thrift store or garage sales. Occasionally I see the need to reinforce a concept with additional worksheets, and I can almost always find something on Enchanted Learning that fits the bill.
There are so many valuable free resources for homeschooling on the internet. Do yourself a favor, and search for free resources before you go buying something. You can print entire unit studies, reading lists, activity ideas, lesson plans, etc. I'll be posting more of my best resources here.
If you always buy printer ink brand new, this approach may be costly. I buy my ink from 4inkjets.com or 123inkjets.com for which you can always find online coupon codes to save you additional 5-20% or get free shipping. I usually end up paying $5-6 per ink cartridge, and even in Hawaii, they get shipped to me within a week.