Pick a telecine machine to fit your budget. Since these devices fill a niche market, they come at a cost, though you don't have to rush out and purchase the latest high-end device. Many smaller, more personal telecine machines exist, but they are limited to 8 and 16mm film. Some older 35mm devices can be found on auction-style listings, however. While the upfront cost is heavy, if you plan on dealing with a lot of 35mm footage, it could be cheaper in the long run.
Decide what resolution you want to scan your film at. Typical resolutions are Standard Definition, High Definition (1080), 2k, and 4k. For most work, 2k is more than adequate. Many professional films are telecined at 2k. However, if you plan on editing your footage on a consumer-level PC or Mac, you may want to stick with HD, as manipulating 2k footage requires a lot of processing power. SD requires the lowest amount of processing power, but HD will strike the right balance between the richness of your 35mm image and (relatively) lower hardware requirements.
Load your footage into the telecine machine. This process will, at a minimum, take as long as the time of your footage itself, though usually even longer, especially depending on what type of telecine machine you purchased and what resolution you will be scanning at. Also, depending on how large a magazine you purchased and how much footage you are processing, you may have to reload the telecine multiple times before you have scanned everything.
Check the resulting digital footage. The telecining process consists of scanning a physical image medium into digital, and thus errors can occur. Make sure to double-check the footage to make sure everything looks okay before beginning the editing and color correction process. Re-scan any footage that did not transfer correctly.
Organize all of your 35mm film footage. Having a production house professionally telecine your footage can be an easier route to go than doing it yourself. However, it will still cost a significant amount of money. Make sure that, if your budget is tight, you collect and organize only the footage that is essential.
Pick the right telecine company for you. Making digital files from 35mm footage is not something that is in demand all across the country. There are a small number of production houses that offer this service. If you live in an area in which there are companies that offer telecining, you may wish to use those, even if one located farther away offers a better price. Shipping 35mm film can be expensive given the amount of footage you are shipping and the weight associated with it.
Provide the telecine company with the digital format you'll want the footage delivered to you in. Most professional production houses will be able to offer you practically every digital format available, so make sure you pick one that will match the system you will be editing on. HD is preferred as it will match most the quality of your 35mm film while still being easy enough to edit on a typical PC/Mac.
Double-check the digital files that are sent to you. A production house that offers telecining will strive to do a professional job, but mistakes can and do happen. Sorting through your newly acquired digital footage early can alleviate many headaches and help prevent you from stumbling upon a telecining error late in post-production.