The Blades, who are winless since the opening day of the season, have had a huge injection of cash following the arrival of Prince Abdullah of Saudi Arabia.
Weir wants to improve his squad as they aim to climb the League One table but will not sign just anyone for the sake of it.
"It is positive news for the football club and everyone has to be happy about that," said Weir, referring to the Prince's investment.
"Hopefully it puts the club on a sounder financial base and it makes us sustainable.
"There is nothing happening in the loan market immediately, we are addressing the areas we need to improve.
"It's a small number of people who are available and we don't want to make mistakes and bring people in just for the sake of it.
"We will do our homework and explore the market and see what is out there and what is relevant for us.
"The work is being done and it is important not to rush it. People will have their ideas where we can improve but it's not as easy as that."