I was tempted to reply to your complete noob thread, but I am noobish myself so I decided to let the more senior members respond.
But apart of that response was to tell you what I consider the mistakes I have made already. I think buying Bachmann sets was one of them. They make the least expensive sets, but you get what you pay for. People speak highly of their Spectrum line of engines in HO, but I have no experience with them.
I was trying to figure out whether I wanted to do HO or N and bought some starter sets. One was a Bachmann N set and the other an HO set that came with the EZ Command. I also purchased a Life Like set, but that was something special that I don't regret (plus the LL engine that came with it is not bad). The Bachmann N set is not good, the engine sucks. But I still liked the EZ track till I spent more money on expensive N remote turnouts in EZ track. In my opinion they are poorly engineered. That is when I stopped buying anymore Bachmann EZ track in N scale.
The HO set came with a manual turnout and overall it looks a bit more stable than the N turnout, so the remote turnouts might be OK in HO. Still I don't like the Bachmann DCC engine that came with the set and have never felt like setting it up a second time, so I did not go down the path of expanding that track. Overall I was fairly disenchanted.
What I was looking for was temporary track, stuff I could set up on carpet or whatever to run some trains for a bit, but then tear down again. The EZ track seemed ideal, but I was having too many problems with it that I almost gave up on the idea altogether. Then I came across thread discussions on Unitrack in other forums and even started one of my own that got great response. Everyone said Kato Unitrack is very high quality, so I took a chance on a Master 2 set in N. I could not be happier, I am having a blast with my trains now and I have decided N is what I will model in, I was leaning toward it anyway and the Unitrack gave me the ability to see what fun could be had in N down the line when I start building the permanent layout, but I could still have fun in a more modest temp layout for now.
If I had to do it all over again, I would buy the Santa Fe Super Chief Starter Set from Kato and go from there.
http://www.modeltrainstuff.com/product_p/kat-106-0016.htm
You will get what you need to start having fun now while you research and find your vision, plus you get a really nice N scale Engine and 3 passenger cars. I have that engine now and it is really nice, I am using it for ghetto freight service till I can start collecting the passenger cars. I bought a Master 2 set, which has a passing siding too, plus the rerailer, powerpack, and turnout controls...just no trains. I can vouch for the quality. I ended up buying more Kato products at a train show this weekend because of how impressed I am with them.
If you choose to stay with HO, I would seriously recommend looking a Atlas starter sets, they have some trackbed track too, but I think the trackbed is removable if you wish to switch to more traditional roadbed later on. I have no experience with them, but I would shy away from the inexpensive Bachmann sets based upon my own experience. Since you are planning a 4x8 anyway, why not just get Atlas track and do the roadbed yourself, or are you looking for something more temporary like I was? Learn how to do Flex track now if this 4x8 will remain up all the time.