Again, being a noobie, I am wondering how big my column lengths should be. Right now I have them set at 650 and 250. What would be the ideal?
I am not a designer, so sorry if I misunderstood this, but are you looking for ideal column-widths & not length? If such is the case, 960 Grids is a much used method to have standardized columns. Take a look - http://960.gs/demo.html Column-lengths should really remain flexible & grow according to the content inside them.
960gs is a little bit to heavy for just doing a 2-column-layout. 960-990px width is what I use most of the time (centered) since 1024x768px is the minimum resolution I work with. The columns itself... depends on what you want to achieve. E.g. 600 and 300px, or same width, 450px... It depends on your needs (I personally like a kind of sidebar... e.g. 150px on the right side).
It depends ofcourse on your layout, needs, content of the columns, ... Without some more informations... hard to say
As a general rule of thumb, you shouldn't be defining the height, especially if you have dynamic content. (The exception is the homepage if you want it to follow an exact design.)
Previous to the 960px standard, the 720px was the norm. I use the 960px width for all of my sites. Typically, the main column is 640px to allow for VGA resolution videos and images. Between the columns, I keep a 20px margin. This will make the sidebar 300px wide, that can accommodate a varity of advertisement sizes and other common widgets.
I usually use the 960gs, i find it to suit my needs. But as said above, it all depends on what you need to put on the sidebars.
I use only 1000 ,no more 960's more people had changed their monitors so 220 780 will be good or 250 750.