Yes, if you just leave the updater's settings as default, you will receive updates in accord with LMDE repositories. Every 6 month or so there are "Update Packs" that are designed and tested for stability - for major system upgrades.
Some of the more courageous users change repos to Debian Testing, for more and more frequent updates, but greater chance of breakage.
If you are inexperienced, best leave all as is, and it will all work and update fine...
LMDE 64b Cinnamon | LMDE 64b Mate | Debian 7 64b | Mint 15 Cinnamon 64b
Dell Inspiron 15R(N5110) Intel i7-2670QM, 4GB DDR3 1333Mhz, Intel 6 Express HM67
GeForce GT525M, 500G SATA, 15.6" HD 1366x768 Optimus on Bumblebee