What version of Premiere Elements are you using and on what operating system is it running?
It is easy enough to record a narration with Premiere Elements with its Narration feature, but for long narrations and planned editing of that narration I would worry about narration track locking and other mishaps that have been reported in recent threads here. The best description that those users gave was the problem for them was associated with a lot of work and involvement on the narration track. I have not experienced the problem first hand.
So, I would second John T. Smith's suggestion to use Audacity unless you want to explore and experiment with Premiere Elements narration on a very mini scale test run basis.
For most of my narration, I use Adobe Audition, edit that Audio file, as needed, then Save to PCM/WAV @ 48KHz 16-bit, for Import into Premiere. Audacity will allow about the same functionality, though I have never used it for such.
I agree with ATR, regarding potential issues with the Narration Track in PrE. Though I have never had any of the issues, I have to admit that, based on the reports here, do not use it very often - usually just for testing. However, even if recording to the Narration Track, it is simple to just Move that Clip, when recorded, to an empty Audio Track, such as Audio 2.
When you say long, can you give us an indication of just how long you anticipate? In general terms, the Duration will not be that much of a consideration, so long as one's destination HDD is formatted to NTFS. If FAT-32, then one can run into the limitation of file size, being about 4GB only.