I am creating Web-to-Lead HTML, and the website captures the first AND last names in a "Name" field. 

Salesforce wants 'First Name' and 'Last Name' as separate fields. I may not be able to talk them into changing the website form to capture these fields separately. 

What's the best way to deal with this? I could create a custom "Name" field on the Lead object and capture this field, but then how would I best break this up into 'First Name' and 'Last Name'