Acer, Toshiba, Lenovo, and Asus are all pretty good laptop brands. I went to Walmart a week a go, and their Laptop prices are inexpensive, so you might find good deals at your local Wal-Mart, but prepared for bigger crowds since I heard it is a tradition for some people in the US to camp out at Wal-Mart to buy cheap stuff on Black Friday.
You should look for a Laptop with a 2 GHz or faster CPU, 4GB of RAM or more, enough hard drive space for carrying all your important files you need, a screen which is big enough for easily reading text 15-17 inches should be good enough, long battery life like 5 hours, comfortable keyboard,
This Acer Laptop for $378.00 at Wal-Mart should be good enough for most or All of your school work : http://www.walmart.com/ip/Acer-AS5733Z-4851/16532140
4GB of DDR3 SDRAM system memory (expandable to 8GB)
Give you the power to handle most power-hungry applications and tons of multimedia work
500GB SATA hard drive
Store 333,000 photos, 142,000 songs or 263 hours of HD video and more
8x SuperMulti DVD double-layer Drive
Watch movies, and read and write CDs and DVDs in multiple formats
10/100 Fast Ethernet, 802.11b/g/n Wireless LAN
Connect to a broadband modem with wired Ethernet or wirelessly connect to a Wi-Fi signal or hotspot with the 802.11b/g/n connection built into your black 15.6" Aspire notebook computer
15.6" HD widescreen CineCrystal display
Intel HD Graphics with 128MB of dedicated system memory and support for Microsoft DirectX 10