"A glass of wine"
Translation:Um copo de vinho
Taça, copo, xícara, caneca, all refer to a different drinking vessel. "Taça" have a stem and a base, used mostly for wine. "Copo" is the most common glass, usually cilindric (used for water, juice, etc). "Caneca" is larger than a "copo", and have a handle (glass and metal ones used for beer, ceramic or plastic ones used for milk, coffee, etc) "Xícara" is like a small "caneca", and can have one or two handles (used for tea, coffee, etc)
As mentioned, when you add some more information, you may use de+o, a, os, as. But that's not a rule. In possessives, you can use both. "O carro de meu pai" = "o carro do meu pai" (the second one is more common. Do = de+o for masculine words). For measurements, you normally just use "de", even if you have extra information. "Quero um kilo de tomates frescos" (I want one kilo of fresh tomatoes), "quero uma taça de vinho Bordeau". If "de" is related to a verb, you normally use just "de". "Preciso de panelas novas" (I need new pans). But if you give much information, you can add the article: "Gosto das casas amarelas da minha rua" (I like my street's yellow houses). I dont think it's a good idea to define rules, once some things work better cause of the sound too, but hope it helps..