Waiting 1 week usually isn't enough. The type of MC999 you received is very easy to get unsuspended from. Call in since you have nothing to lose at this point and recap what the email says to the rep and they will go on about how they do this to all new members (that's a lie - I have had this happen only once out of all of the stealths I've created in the last few months) and that they want to talk to the owner of the account. You'll likely be asked information on your account (your stealth address probably) so have that handy.
Then they'll ask what type of items you're selling - be honest and tell them about the books. Make sure you emphasize they were used, old books because with this question they're trying to see if you are someone who buys things and resell them (that's okay, but you'd risk having to send in invoices if they think that).
2nd question usually is where are the items located - say your house, your room, or anything that implies it's in your possession now. You don't want to seem like you're dropshipping.
3rd question can vary but usually they ask how long it will take for you to ship your item? Say the next day. Instead of this question, they may ask how will you be shipping this item? Hopefully you remember what shipping method you selected for your listing, otherwise just say the USPS.
Sometimes it ends there, sometimes theres a 4th question. They may ask where do you get your items? Again, they're trying to see if you're a reseller. Say it's something you already own and you've owned it for years. It's your personal item you're trying to get rid of. They sometimes ask item specific questions, like if your book is a rare collectible (like an autographed copy), they would ask can you provide a COA? Say yes even if you can't.
These questions are very straightforward to answer if you know how eBay thinks. They can vary slightly but those are the most common questions. Just stay calm and you'll easily pass. If this is the first time you've ever called ebay for something like this, I suggest practicing saying your stealth info outloud before you call. You want to sound confident when stating your stealth address.
After the questions, the rep will then do one quick check of your account - since it's brand new you have nothing to worry about, and then you'll be unrestricted.
To avoid this in the future: as said above make sure to use all new info. I would use a prepaid phone instead of a texting app if you're doing that. It's best to have your Paypal verified with a vba before trying to sell. Don't forget to do "new user" things with your account - search for random items, add them to your watch list, click on random help links. Make sure you seem like a new user to them. Also, bid on a few items that you never expect to win such as expensive electronics that start at 0.99 or something. Do this slowly over the course of days, or even weeks.
And I'd wait longer than a week before trying to list. 2 weeks is my recommended minimum though I usually wait a month.
From reading your post, it seems like you didn't really make any mistakes except for listing too early. Listing books is perfectly fine btw - I always have, and still do use that as my first item and have avoided MC999s 99% of the time. The type of phone you used to verify your account could have led to the suspension, and/or not having a bank attached to your account could have as well. Or maybe you forgot to link your Paypal account to your ebay account. It could have been the time you took before listing and item, or a combination of all of the above. Ebay, like all companies have a formula they use to calculate risk of its members. It could be one big thing you did that set off their bots, or a few small things.