Okay. I am not new to CCGs: I have played Overpower extensively, and Magic casually, but I have never played in official tournaments, local or otherwise, and I am curious as to what I need to do to compete on every level.

Do I need to find local tournaments, build up points, and then enter larger (nationwide) tournaments? Any discussion regarding the ins-and-outs of tournament play is appreciated :)

not exactly, as you play offical tournaments to get points and get ranked world-wide, regional tournaments can be hosted anywhere really, and if you do really really well in those, you get an invite to a national event

so basically, find as many local tournaments and enter them to build up a point base, and then find regional tournaments and play in as many of them to build up a larger point base, and then hope i get an invite to a national event.

so it really comes down to finding out when and where the tournaments are and entering them. my guess is local tournaments can be entered the day of (show up, pay the fee, and play) and regionals have to be signed up for ahead of time. correct?

Basically Yes

You'll want to check with the TO (or PTO in the case of an event like Regionals) about seating for events. If it's a local tournament being run at a store, usually you show up, pay, and go play. For Regional tournaments more often than not there's Pre-Registration, but it's not REQUIRED to play in the tournament. For instance for Yu-Gi-Oh!, I had about 40 people Pre-Register and almost 100 show up and pay the day of the event. That's about normal for an event like that. (Others who had limited seating however ONLY let in people who Pre-Registered and sold out of seats through Pre-Registration.) For something like a Pro Circuit event, you need to be qualified either by having a high enough ranking (generated by amassing rating points) or by winning a Pro Circuit Qualifier.

I'm curious, but is Upper Deck planning to have a place to post and/or find local tournaments?

There seem to be innuendos as the UDE having a specific site where people can go to find a local tournament; similar to what they had with Yu-gi-oh, but in the meantime ask you local retailer whether they will be hosting tournaments. Our store has already begun hosting weekly tournaments for Marvel. We had a Sealed booster draft last Saturday and are having another one this week.

UDE will most likely have some tournament locator up and running in the near future. Major events like Convention Championships and Qualifiers will have their own specific page most likely. This is of course a guess, but probably an educated one. ;)

hopefully they will begin posting the schedule soon...

i've already heard of two qualifiers in SoCal, one in San Diego over the Memorial Day weekend, and another in Long Beach in the middle of June.