I am trying to get pics off of an SD card. I plugged in the adapter into the USB port. Where do I go to download these pics onto my laptop?

There's usually a couple of folders on a camera's SD card. Assuming the card appeared on the desktop as a drive, double click the icon to open it. Then open the folders on the card until you find the one containing your images. With most cameras, those would be the files ending in .jpg (JPEG images). Copy them to the hard drive.

By default, the Mac OS does not show mounted drives. A very strange "default", if you ask me. Click on the desktop so that the title next to the Apple at the upper left says Finder. Then choose Finder > Preferences. Under the General tab, turn on all four check boxes under "Show these items on the desktop". If your SD card reader is already plugged in, it should now appear.

Some USB card reader adaptors can be fussy. Unplug the adaptor. Remove the SD card and try seating it again, making sure it's all the way in. Plug it back into the Mac and see if it appears.

If it still doesn't work, it could be the reader. Especially if it's an older one. Depending on how long you've had it, older readers can't see an SD card above a given size. I had one that couldn't mount any card larger than 2 GB and had to get a new reader.

Zapping the pram may work or just restarting your computer after repairing your desktop.

Resetting your Mac's PRAM and NVRAM

http://support.apple.com/kb/HT1452