You can read a lot on google about stuff like this, but basically, yeah, don't close any accounts unless they have annual fees attached to them.
2 factors in your credit score are average length of history and your utilization. If you close an older card, it drops your length of history down, and the history becomes an average of the cards your currently have.
Utilization is a very important factor in your credit score. If you close an account, it drops your overall credit limits, therefore automatically increases your utilization. i.e. 15k in debt on 50k total limit is 30%, 15k in debt on 30k limit is 50%. You get the picture.
When I was younger I went on a credit binge and opened up many accounts, which I still have. You should keep all your cards, but make sure you charge something on them at least like once every 6 months to keep them active.
I actually use most of my cards on a regular basis. Most of them are rewards cards that give you extra points on different things like gas, entertainment, restaurants, etc.
I try to stay current on all my credit cards so I don't have to pay interest. I will alternate cards depending on the date of the month so that I can get the most interest free days I can. You do this based on the statement date of the card.
For example, the statement date on my chase card is the 11th of every month. On that date a new cycle begins. Anything you charge after that date, you don't have to pay for almost 2 months, because the amount due next is based off the period that just ended.
On the 24th of the month, my Amex statement comes and I start charging stuff on that. It gives me about a week longer than I would if I had charged it on the Chase, so I can get another paycheck in.
I probably rotate 3-4 cards like this. I have another 3 cards that I paid 3% in fees for to borrow cash interest free for 12-15 months. I just keep those in a drawer. I make sure I have enough money to pay those off when due, or I borrow against another card to keep the cycle going.
As you can probably tell, I don't gamble anymore, but I keep up with the residual credit card accounts I opened during that time.