Familiarity with the various materials and equipments involved in screen printing t-shirts will surely help the novice to start him on the right track.
For waterbase textile inks, he/she can stock screen mesh starting from 100,120, 135 and 150. For plastisol inks, you can start from 180 to 305 mesh. Knowledge about additives, reducers, pigments, etc. will surely help. Drying equipments such as heat gun and heat press should be secured.
A workable exposure box with the right UV output is surely a must-have.
For squeegees, 60-65 shore or duro will surely bring the best prints for warerbase textile inks, 70-75 shore polyurethane squeegees will help bring out the highest quality prints for plastisol printing, whether spot colors or CMYK printing.
Knowledge about the compatible photoemulsions for every job is required in order to accomplish the highest quality output a screen can resolve. A good color separation knowhow (Photoshop) or similar software is a must if you want to bring out the best quality output from your prints!
For starters, portable platens, and line tables will help your small scale t-shirt printing business running. Happy Printing & Cheers!