Okay, first things first. The 10 refurbished laptops. If they work, don't mess with them. Most people will know Windows better, and using Windows will be better for them. I'm not saying Ubuntu is bad, simply Windows will probably be more familiar. Windows 7 isn't a bas OS - and if you can get the free Windows 10 update, even better.
The wireless printer - we need to know the brand. Some it is easy to get working, others less so. Essentially, this guide is what you need.
Finally, MS Office 360 won't run on Ubuntu - Microsoft only provide Windows and OSX installation programs. Depending on what you are doing, Libre Office should fulfil your needs - it has all the basic programs and comes pre-installed on Ubuntu releases
Alternatively, to avoid compatibility issues you can use MS Office online.
The issues with the computers may not fix themselves with a new OS. We need to know what you are hoping to solve - and maybe ask over on Super User, one of our sister sites for Windows questions. Also, if you can get the aforementioned Windows 10 for free, that may fix the issues.
Now, if you do decide to go for Ubuntu, I'd reccomend 14.04. It's what I'm writing this on, it's a stable release and it's supported for 5 years in total - until April 2019.
For an easy to follow install guide, this question and answer is your friend, and if you encounter any issues then pop back here and ask a new question!
While Ubuntu (which by default uses a "Display Manager" called Unity) isn't a lightweight OS, it doesn't need much to run well. I can put up with it on a PC with 1 GB of RAM, but I'd advise 2 or even 4 GB.
If you have less than 2 GB of RAM, or an old processor, consider using Xubuntu or for less that 1 GB Lubuntu may be better. I'd suggest reading this answer - it explains why it would be slow, and what you can do to speed it up. That said, anything that run Windows 7 acceptably should be fine with Ubuntu!
Good luck with your project, and remember to ask another question if you have any specific issues, or comment here and I'll do my best to help.