You can find a list of capacitors and other analog board components here: https://docs.google.com/spreadsheets/d/132RwzC8HM5ask-BdY_31txErOCwJDSkz099GY2XLpE0/edit?hl=en&hl=en#gid=0
This list is maintained by James Wages. The analog boards for the 128k, 512k, and Plus are compatible with 3 different revisions. Digikey part numbers for replacement parts are included. The first tab lists the capacitors most likely to need replacement, and the second tab lists all capacitors.
You're looking for capacitors that are bulging or leaking. A lot of people just replace all of them, or at least all of the first page ones, because the extent of the leaking often isn't revealed until you remove the capacitors and can see underneath them. For components besides the capacitors, you're generally looking for anything burnt or physically broken (such as diodes and transistors). Almost always you will want to re-solder the pins on the flyback transformer and all the connectors (J1, J2, and J3). These solder joints were notoriously bad.
The capacitors on the logic board have not been observed to leak. The logic board generally doesn't require attention unless the battery has caused significant corrosion. So if there is still a battery present, be sure to remove it.
The CRT and PSU circuitry contain high voltages. If the computer has been turned off for an extended period (years, as you indicate), the CRT capacitors have probably discharged. However, I always follow CRT discharge procedure when working on a compact Mac analog board. See https://archive.org/details/manuals-apple-safety for details. On the PSU side of things, there is a bleed resistor that will discharge the PSU capacitors within a few minutes of being turned off (but still plugged in).