Gapps are a necessary evil. Rom creators are not allowed to prepackage them into Rom builds because they are the proprietary property of Google. You won't be able to use your custom rom to its full capability without installing Gapps along with the rom since the Gapps package contains all of the Google apps including the Play Store. Most Rom developers will make note in their release thread that you need to install Gapps, but may or may not direct you to the proper download. It can be hard to find the correct version on your own. It can also be difficult to discern whether or not the site you land on with a "download link" is safe. CyanogenMod has made finding and downloading the proper Gapps package super simple. They have put together and now maintain a Gapps wiki thread. There you can find all versions of Gapps all the way back to CM7! Bookmark the link below for Gapps downloads.
Via wiki.cyanogenmod.org
