mass effect 2 question!

Hoe can i recruit head scientists? and were do i go to upgrade my weapons? i already have them i just dont know how to apply them thanks

and how can i get heavy weapon traningg?

The scientist is one of the people you have to recruit, he's in the Omega Nebula.

Once you recruit the scientist (Mordin), go to the technology lab on the Normandy and on the left there is an upgrade desk. Select the upgrade you want. It costs minerals so you have to scan planets for more and find more when doing missions.

In your ship there is a technology spot where you can do upgrades,etc..

The only scientist is Morin. Just talk to him, investigate, [UPGRADES] and you will be able to buy them using the minerals you can collect on the planets. The weapons training, you can't "learn", each class can use a certain type of gun.Hakud0ushi

Actually use the terminal that is called "Resaerch" to purchase upgrades. The "Upgrades" terminal just let's you look at what you've upgraded already. Also, I do not believe there is Heavy Weapon training, only upgrades for Heavy Weapons.

EDIT: Forgot to specify where it's at. The two terminals are in the Tech Lab on the 2nd level of the ship. It's the room with the Salarian scientist named Mordin.