My husband lives here in the US. We know he's eligible for a VISA based on our marriage. How long will it take from the time we file the I-130 to the time he actually has his VISA in hand?

what visa are you talking about? Immigrant visa?

if you are talking about a green card, it's not really a visa, but your husband could get an immigrant visa to come to the States to get a green card (which is a permission for permanent residency). But since your husband is already in the States, he should simply do adjustment of status.

read www.uscis.gov

Now, are you a citizen? is he in the country legally? did he come with a non-immigrant visa and was inspected at the point of entry? Or did he cross the border uninspected by an immigration officer?

Usually it takes less than 20 years.

In some cases it might take as little as 1 year.

A visa is only to *enter* the country. If someone does not need permission to *enter*, they don't get a visa. If you are a USC and he entered w/ inspection and is not otherwise inadmissible under 245, then it will probably take 3 months for him to get work permission, and 1-2 years to get reseidency.