How Time Machine works

I was in this exact situation recently. I just bought a new rMBP 13" to replace my aging white early 2008 macbook. I had used time machine to back my old computer up. I did not want to restore everything. I called Applecare and they walked me through the steps. For me it was a bit complicated ( I am not good with stuff like that) but he walked me through it and I was able to cherry pick the files and all of my photos. I wish I could remember what the steps were. I am sure someone here is much more savvy than I.

 

You can use TM in conjunction with Migration Assistant. Migration Assistant gives you the opportunity to restore apps, system settings and data from another Mac or a TM backup. You can choose all 3 or a subset of the 3. However, when you pick one it's an all-or-nothing proposition for that restoration.

If you choose data, it will migrate your account over, so you'll want to make that decision when you first boot the system (MA comes up as part of the initial config).

Here's the Apple Support article on Migration Assistant

 

Well, the idea of TM is that it's a backup tool, not a data transfer tool. Apple allows you to use TM as a transfer tool through the use of Migration Assistant, but the idea is that it's a disaster-recovery situation and you'll probably want all your stuff back when you do the restore, hence the lack of selectability when choosing the data to restore.

You DO realize that if you don't restore all your data from the TM backup it will likely eventually get deleted, right? Doing what you want to do, you're associating the old TM backup with a new Mac, the new Mac will then start using THAT TM backup and will eventually delete old data that doesn't exist on the new Mac as space is needed on the TM drive.

 

If you want to narrow down the backup to certain files, in the Time Machine preferences, click on options button and add what you don't want to be backed up. You can browse the Time Machine backup and pick and choose what to restore manually. If you want you can just pick a single file, just drag and drop it from the Time Machine backup.

Also, it is a good idea to do a secondary backup. I have had a backup drive fail on me so having a secondary backup is helpful. The other aspect is if to keep the secondary backup outside of your house in case of a fire.