Useful keyword research tool – and it’s free.
Scout Suggest is a free keyword research tool. It’s quite handy for putting in a seed term and then getting a list of suggested search terms – it’s based on Google Autocomplete searches. Note that it is only a list of terms (it’s free after all) there’s no indication of competitiveness, search volume of the value of the terms. Scout have a paid tool that includes all this (but full disclaimer: we haven’t used the paid tool as yet).
If you’re looking for a good guide to the value and process of keyword research then this guide from Moz is worth a read. Note: Moz have their own keyword tool as well – with a free offering and paid upgraded version – we’ve used it and it is very good.