Read This Before You Finish Your Basement

1. A rechargeable portable light, stored in an easy-to-find spot, in case of a power outage.
Oxo Candela Glow rechargeable lights, $40 for a set of two.

2. A cell-phone signal booster so that you can take and make calls below grade.
Wi-Ex zBoost SOHO, $190; Amazon

3. A wireless-network extender so that you can tote 
your laptop downstairs.
Netgear Universal Wi-Fi Range Extender, $80; Best Buy

4. A wet/dry hand vacuum in case of small spills or washing-machine snafus.
Hoover Wet/Dry Cordless Hand Vacuum, $30; Walmart