I've been drawing traditionally all my life, but I really want to get familiar with digital drawing as well.
If there are any tips and tricks people know on how to use programs like Paint Tool SAI and Photoshop, I'd be really grateful!

I don't know anything about it personally but my friends usually talk about how useful video tutorials are and they're easy to find too, just look up what tutorial you want on Google or YouTube :)

Maybe starting with GIMP would help you understand other projects like Photoshop or SAI.
That's how I started and I use both Photoshop and SAI now :D

i was actually a traditional artist ever since too, then my best friend at school started introducing me to digital art. at first it was really hard for me given that i dont have a drawing tablet to start with (i still don't have even up to now) but years of practice ( i had been drawing digitally for almost a year) and i guess like >>2 said, watching different tutorials and such could help you :) here is a sample image of different brush tools in SAI (for me it is easier to draw in SAI tho, just my opinion)
i hope this helps :)

I was a traditional too. What you need to pass to digital is graphic tablet and the knowledge that you can erase an action. The rest can be like in traditional painting.