The current file limits are 240 minutes and 500MB.
This limit is more than enough for the majority of content however, some file formats (WAV in particular) can produce unnecessarily large file sizes.
Re-exporting your clips as MP3 from WAV will give far better compression. (As a rough guide: a WAV saved at 48k bit rate can takes up around 6MB per minute - the same 48k file as MP3 averages out at just 0.4MB per minute.)
Audacity is a free, open source desktop editing software for Windows and Mac that can convert many different file types.