The 26-year-old put pen-to-paper on a three-and-a-half-year deal from West Brom on Friday, having originally seen the move collapse in September.
With fellow Republic of Ireland internationals Robbie Brady, Paul McShane, David Meyler and Stephen Quinn already plying their trade at Hull, Long said the decision was made easier.
"I got in touch with the boys and asked them about the club, the manager, training and other things," Long told the club's official website.
"They only had good things to say about everything and they're all enjoying their time with the club.
"It's an exciting time here with it being the first season back in the Premier League. The team has shown they are good enough to be here and now they're adding to the squad. Hopefully we can move the club in the right direction."
Long also revealed that he spoke to former West Brom team-mate Boaz Myhill, who enjoyed a seven-year stint at Hull between 2003 and 2010.
He added: "Boaz had good things to say as well.
"He was telling me about the area and where he lived in Kirk Ella. Learning about the area was a big factor for me because I want my family to settle here as well.
"If I'm happy at home, I'll be happy on the pitch so hopefully that part will be settled quickly and I can concentrate on my football."
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