Hi Ragen,
Apologies for the late reply. We actually have a Lead Reports screen. You can use this to get a report of your leads. It can be found in Leads tab > Lead Reports. Unfortunately, there isn't a filter for when the lead was created. You can however customize the screen to add that yourself. The screen you'll need to copy and customize is the CRM_LeadReportsV2. You can take a look at the filters in place and use those as a guide to create yours. The actions for filtering are found on the Generate Report button. The field you'll probably want to filter for is "CreatedDate". If you're unfamiliar with customization, you can go over our Customization Webinars.
You can also create your own report template or modify the existing ones. I'd start by going through the Report Designer tutorials first to get a grasp of the Report Designer. You also have the option of createding your own button and generating your own report if you desire.
Another completely different way to go about this would be to have a grid that lists your Leads. You can then use the grid to filter for a date range based on the "Created Date" I mentioned earlier and the Next Activity field. We then have a Export Grid to Excel action that you can use to get a speadsheet of your leads. This is a bit of a messier way to do it, but also perhaps a simpler way.
Hope this helps,
Adam