More details would definately be nice. I can think of a few very nice options that would work over wifi.
Airdroid2 would let you upload and download files over your browser pretty handily, though a web interface. It does a load of other things too (like act as a filemanager, and let you do things on your phone like send texts from a webui)
Another alternative would be pushbullet – it lets you send and recieve files up to 25 mb. Like airdroid, it uses a webui on the PC side (or extentions, which are well worth getting IMO) , and an app on the phone
You could also use a sync tool like dropbox or (my current favourite) bitorrent sync to expose a folder and download files from there.
There are plenty solutions for that. Unfortunately, you didn’t specify the options: WiFi? Bluetooth? USB only? Other means?
A first check should bring you to our nice file-transfer tag-wiki, linking to questions already having answers on this topic:
- How can I send a file wirelessly without bluetooth or a Wi-Fi network in ICS?
- How can I transfer photos to my Android Jelly Bean device while preserving the original timestamp?
Also, the “Related” section of your question (to the right, if you use a web browser) has some pointers. And of course there are already several questions tagged file-transfer (just click on the tag): Is there a way to copy files directly between two Android devices on the same wifi network? would be one example.
If WiFi is an option, you might want to take a look at Airdroid. That’s an app you install on your Android device, start it, and it gives you an URL to type into your browser on your Mac. From there, you can manage your device easily: copy files to and from, check the call log, write an SMS, and much more.
If your device (which you did not mention) has an SDCard, you could also unmount that, put it into a card reader, and attach that to your Mac. Then copy the files to the card, safely unmount, and put it back into your Android device.
For more/other options, please follow the links above – or use the search box 🙂
You can use an app called Android File Transfer, where you connect you device to your computer through USB and then you can just drag the files into the application. They will be transfered in a matter of seconds!