There was a thread on this last year that was very helpful to me, since that was my first trip there. Here are my lessons from last year.
First and foremost, just go if you can. You can find tickets. Hotels were tougher.
Overall, you can spend as much or as little as you want. You can stay downtown and get nice seats every game, or you can stay in Iowa and get Gen Admission tix every game.
Tickets :
Agreed on previous post about last-minute tickets. We got ours the day before for about $100, and could have gotten for half that an hour before the game started.
There is an app called "primesport" that you can buy tickets on, and an app called "Flash Seats" that works with it. You buy tickets on PrimeSport, and then there was an option to send them to "Flash Seats", and the ticket shows up on your phone so they can scan that. I was paranoid about this process, but it worked nicely. I think you need to set it up before you go, to be safe. And they have an outlet at the stadium in case you have any issues.
OR : You can get Gen Admission tickets booklets and go to any game. Our fans travel and will show up, but not all do. The line for our 1st game was a mile long, but I was able to walk into the Florida/UT game in the 1st inning with no line at all. It's a great way to watch games that you aren't as interested in. These are $10 each I think, or you can get a package of 10 tickets for $80 or something like that. They sell them at Hy-Vee grocery stores (and none of our hotel concierge folks knew this, but 6pack message board did)
OR : You can go to the box-office the morning of the games. Show up before 8:30 and they give you a place in line. This didn't work well for us because we had 6 in our group and they would only sell tickets in groups of 4 or less. You may want to google details. This site was helpful to me last year :
https://www.ncaa.com/championships/baseball/d1/ticket-questions
Stadium beer :
I'm a beer snob. There was 1 place that sold "craft beer" that was behind home plate. So if you sit in outfield, you can either walk far for good beer, or not-so-far for lite beer. Prices are average stadium prices.
Parking :
There is a lot next to the stadium that apparently fills up early. People tailgate there and it's a good scene overall. I think it's $15. I parked there for the first game, but it took forever to get out after the game. The next game we used the hotel shuttle and saved about 30 minutes getting out. There is also ample parking on the West side of the stadium on the side of the streets, but it also fills up. It's fun to get there early and enjoy the crowds and local bars.
Hotels :
I think I paid $400/night or close to that, close to downtown but couldn't walk to the stadium. Across the river had more availability for much less $$. Honestly I'd probably do that for my next trip, but was willing to pay for my 1st time. It may be a little more effort getting back to the room obviously.
Misc :
I took my 9 and 11 year-old last year, and it was their first college baseball game.
Omaha zoo is great, and I usually don't like zoos
There are lots of activities around the stadium to enjoy, especially for kids.
Locals seem to have preferred the Rosenblatt days, saying the new stuff is too corporate and the $$ is too centralized. This may be true, but it's still done very well.
There are a LOT of people who just go to the series regardless of what schools make it. Folks who just like baseball and live in the area. I thought that was pretty cool.
I loved our experience last year and only stayed til Tuesday (saw 2 MSU games, and 2 others). I'd love to go back this year.