As a hobbyist woodworker, going to the local woodworker supply store and buying a board or two and some supplies at retail, as you need them, is convenient, fairly affordable and sensible. But as you move into production work, you expect to find suppliers that can get you what you need in larger quantities and at better prices. The biggest disappointment I encountered when changing from hobbyist to professional woodworker was the realization that purveyors of most of my supplies were not willing to extend to me the same level of discounts that retailers expected me to offer them on my goods. While I'm expected to offer 40% to 60% discounts to wholesale buyers, the "wholesale" outlets offering the glues, finishes, and shop supplies I use only discounted the retail prices by 5% to 10% unless HUGE quantities are purchased; like 100 cases of lacquer per order. A small business, just starting out hasn't the resources or the need to purchase in such volume.
Who supplies your needs will depend on your location, what you are in need of, and how much room you have for storage. If you have room to store large amounts of lumber, buying in quantity will slash the price. Buying fresh sawn lumber directly from a mill in quantity and drying it yourself will slash it again. Buying finishing supplies and glue wholesale in multiple case lots saves you some money over retail prices. The larger the quantity you purchase at one time the larger the discount. But how much is too much; is it worth buying a 5 year supply of glue to save a couple of dollars a gallon? If you can't use large quantities yourself, try banding together with other shops in a cooperative and pool your purchasing power through quantity buying. Or you can try a sideline of reselling your excess stock at retail to hobbyist woodworkers. If this is not possible it may be most convenient to stick with the retail suppliers you've used all along for your general shop supplies.
For supplies you are willing to purchase in large quantity I have found that the best way to find reliable suppliers is to go to other woodworking shops and ask who they use. If that's not working for you decide on the brands you want to use, contact their sales support team and ask for wholesale suppliers of their products in your area. The Internet is also a great way to ferret out suppliers. Although most of the hits you receive will be for retail outlets, if you ask them, many will set up a wholesale account for you if you have proper credentials as a legitimate business. Just don't expect big discounts.
Woodworking trade magazines also carry advertising for wholesale and factory direct dealers of an assortment of things. I'm not talking about the magazines you see on the magazine rack at your corner grocery store, I'm talking about trade mags, those published for professional shops. As a bonus, unlike hobbyist magazines which cost an arm and a leg, many of the trade journals are available at little or no cost to you. I find these ones useful.
Wood Shop news (woodshopnews.com)
Cabinet Maker (cabinetmakeronline.com)
Wood Digest (wooddigest.com)
Finishing Magazine (pfonline.com)
Wood Design & Building (cwc.ca/Publications/WDB+Magazine)
Custom Woodworking Business (iswonline.com)
The above are web sites. Some allow you to read their magazines online. All allow you to subscribe to the printed versions. There is nothing wrong with the hobbyist magazines; most have many wonderful tips, techniques and project plans, and I subscribe to several of them myself but they are rarely a good source for wholesale suppliers and that is, after all, what we are discussing here.
Just a word on wood screws. Sometimes you can get a good price on wood screws from a local lumber yard by having them order extra stock for you in boxes of 1000. But try their screws out first. Most lumber yards I've visited stock a hot stamped steel screw that has very little strength. They work fine on construction lumber like pine, but when used in hardwoods they twist off easily even when proper pilot holes are drilled. I find life much easier when I use high quality milled steel screws that don't twist off. At least, not without putting a lot of effort into it. I especially like the dry-lube finish screws that eliminate the need for waxing. I pay a tad bit more for these but when bought in quantity they are still quite economical - especially if you figure how much it costs in time and labor to dig a twisted-off screw out of your project and repair the damage.
As you move more into the wholesale world, you will encounter some brands you have not tried before, brands that target only professionals woodworkers. Some will offer samples of their product to determine if you want to buy in quantity. Get the samples. Try before you buy a years supply of something you may be disappointed with or don't know how to use.
Finding suppliers is often a slow process. Where you buy will depend on what you buy, how much of it you can use within the products shelf life and how much storage space you have. Buying wholesale is always cheaper than buying retail, but you will be expected to buy in large quantity to get a meaningful discount.
Seldom will you find one supplier, wholesale or retail, who can fill all of your needs. Keep a notebook - either on paper or in your computer - of what you buy from which supplier along with SKU numbers and prices. This will save much frustration when it comes time to re-order. Reducing frustration is always a good thing!
Douglas Bittinger has been building custom fine furniture for over 25 years, and has been lead repair tech for a major furnishings retail store chain.
Along with his wife, Marie, he currently operates
Smoky Mountain Woodworks
in Edwina, TN.
For your convenience, here are links to all the articles in the "Going Pro as a Woodworker" series:
Taking the Plunge into Professional Woodworking
Right For You?
A Suitable Workspace
Finding Good Suppliers
Marketing Your Work
Retiring to Management