Transferring Data From MacBook To iMac

I'm not exactly sure what category to file my question under due to it's unique circumstances, so I tagged & selected areas & categories that I thought were appropriate to widen the range of people who will see it & hopefully, make it more likely that I'll find the answer I'm looking for.

I was given an older iMac computer by a family friend, it's old enough to not have an iSight camera built into it, but new enough to have well-working wifi & Bluetooth connectivity available on it & support it's updated software without posing any problems. I believe from what I can gather & the looks of it, it's currently running Snow Leopard, but I can't be completely sure because the newer software was installed previously, before I received the computer, although I'm pretty sure that it is Snow Leopard.

I also have a MacBook that stopped taking a charge long before I got the new (to me) iMac, the repair is not worth the cost, so I would like to transfer the data from my MacBook (irreplacable pictures, music, etc.) to the iMac, I'm planning on purchasing an external hard drive & an external battery charger, but I can't afford it at the moment & would like to transfer the data as soon as possible, so that I can access it all again, but there's only so much battery life left on my MacBook battery right now, about 10% at the very most, which is certainly not enough to keep the computer on long enough to transfer it all with file sharing via wifi/Bluetooth.

So, I was wondering if I could possibly connect the two through a USB cord & transfer it without the MacBook being turned on or if there was any other way to transfer information without having to turn on the MacBook to do so?

My MacBook has a unibody & was purchased brand new in about mid-2010, it was either the last or at least, one of the last models of MacBooks made before MacBooks were discontinued, & it also runs Snow Leopard. I could never figured out how to work Time Machine & from what I could figure out from the program it either cost money to use/I didn't have any external place to store a large amount of data, so no, I don't have a working Time Machine because I never could set it up. I don't what might have relevance to my situation or not so, I tried to give as much information as possible in case it could be helpful.

Thank you all so much for your time, input, & help, I really appreciate it! (: