Newbie here - need help picking a desktop for < $1000

The workhorses.

http://www-304.ibm.com/shop/americas/webapp/wcs/stores/servlet/default/CategoryDisplay?categoryId=2576395&storeId=1&catalogId=-840&langId=-1

A monitor will be seperate.

Acer Aspire AM3300-U1332 http://www.newegg.com/Product/Product.aspx?Item=N82E16883103244 $599.99
ASUS VW246H Glossy Black 24" http://www.newegg.com/Product/Product.aspx?Item=N82E16824236049 $219.99

Good reviews and total cost is $819.98 (not including tax and shipping)

Your $1000 budget should buy you a pretty decent rig.

Having experience with those three makers, your best bet for a decent machine would be HP. Toshiba has ceased production of desktops but the desktop replacement laptops are pretty hefty and can indeed fill in for the tasks your seeking.

HP Pavilion Elite HPE-450t base configuration $999.99 + $200 for a 25" monitor
http://www.shopping.hp.com/webapp/shopping/computer_can_series.do?storeName=computer_store&category=desktops&a1=Category&v1=High+performance&series_name=HPE450t_series&jumpid=in_R329_prodexp/hhoslp/psg/desktops/High_performance/HPE450t_series

? Genuine Windows 7 Home Premium 64-bit
? Intel Core i-5 760 Processor (2.8GHz)
? 8GB PC3-10600 DDR3 SDRAM
? 1GB DDR3 ATI Radeon HD 5570 graphics
? 1TB hard drive
? Blu-ray player and SuperMulti DVD burner with LightScribe
? 802.11b/g/n wireless LAN

It's a fairly high-end machine, with ample power; more then you'll need, so its pretty much future proof, and if they make HP's the same way the did 8 years ago, it should last you at least 8years, I have a old Pavilion a705w thats still going strong with original parts.
I would recommend purchasing somewhere near the top of your budget anything with a quad core (multi-threaded apps are the future). Most systems now days come with 4Gb of RAM as a minimum, plenty for web browsing, word processing and such. You'll want to look for a system with a dedicate graphics card with at least 512mb of memory, especially if your looking to watch blurays. More manufactures are shifting to providing a terabyte of storage space, more than enough in your case I believe.

Preferably an HP, plenty of options under $1000, Dells are decent, and I would stay away from Gateways (Acer). If your really feeling frisky you can look into building your own system.

If you would consider a Toshiba machine, their Satellite and Qosmio lines of laptops are great. The Qosmio being a desktop replacement. You can always output to a larger external monitor and purchase a external keyboard and mouse.

Satellite $899
http://www.toshibadirect.com/td/b2c/pdet.to?poid=483108

Qosmio base model $1289