"...thinking of building my own rifle..." Start by reading every gunsmithing book you can. You might find some in your local public library. Your local gun shop or Amazon otherwise. Gun shows are usually good places to find books too.
If you're planning on doing all the work yourself, you'll be needing some tools. None of which are exactly cheap. A barrel vise with bushings runs $299.97US from Brownell's. $64.04US for a generic action wrench. A large ring Mauser action wrench runs $109.97US. And you'll need headspace guages. $25 or $30 USD each. You'll need the whole set. About $450US with the generic wrench, so far.
Gets expensive for a one time build. Most builders have the barrel installed by a smithy and do the rest themselves. Stock fitting, trigger installation, etc.