Micah Richards has warned new Aston Villa team-mate Fabian Delph over a possible move to Manchester City.
Inverness have announced the signing of former Aldershot winger Jordan Roberts.
The 21-year-old has signed a two-year deal at the City Ground with the option of a further year.
Forest boss Billy Davies expects Paterson to adapt quickly to his new surroundings as Forest hope to push for promotion this season.
Davies said: "We are delighted to have Jamie on board. He was very impressive for Walsall last season and has good pedigree.
"He's quick, agile and has proven himself as a composed figure in front of goal. He adds another dimension to our attack.
"While Jamie is undoubtedly an exciting prospect, he has already gained good first team experience and that should help him make the step up to the Championship."
Paterson could feature against his old club on July 23, when Forest travel to The Banks's Stadium for a pre-season friendly.