Hi Stan.
First off, don't do anything for a month! Just read the forum and then think about what you want.
Do you know what you want to model? I often suggest that you go with the time and place where you first found you were interested in trains -- for most of us, that's between ages 8 and 12.
Picking HO is good. That's one big decision outof the way, and often the least important one. HO is a nice middle-of-the road choice, and you can go almost anywhere with it.
A 4x8 layout is a good starter. A 5x9 is slighly better, but sometimes harder to justify or find. There are many pre-done track plans for this size; use your month to explore track plan books, track plan web sites. You'll not get anything much more complex than a loop or a figure 8 in the space, unless you like small trains. Worst problem with a 4x8 is reaching across it.
Don't expect your first layout to be your last. Lots of people don't finish their first layout before they start on their second. Check out the track planning threads.
Don't buy a train set. It may seem to have everything, but usually not top quality or even middling quality.
Go to a train show. Go to a railway hobby shop.