I ride a bike

The first:
Ok, so I'm new to the idea of maintaining my own bike in any capacity, though I've been riding around town for about five years now. However, I'm really excited about the idea of being able to work on my bike myself, and, if nothing else, be able to tell the mechanic what's up when I take the guy in for a tune up. I even bought a book: The Bicycling Guide to Complete Bicycle Maintenance & Repair (sub-question: I bought the book because it was $6; is it worthwhile?) So far, I have basic tools: an allen wrench set, some screwdrivers, an adjustable pair of pliers, and an old toothbrush to clean out the grit. All I've really done is clean up my bike with mild degreaser (Simple Green, one of the book's suggestions) and change out the pedals. The tools I have are enough for what I've been doing. Is there anything else that everyone who wants to (attempt to) keep their bike up should have? Should I look into a multitool?

The Second:
Sometimes, when I stand on my pedals (ie really put some force into them) I hear a slight clicking sound coming from the crank axle/bottom bracket area. The guy who last tuned up my bike said it might be that the crank axle isn't snug against the bottom bracket (or something like that.) I think it may also be related to the grit that has gotten into the area. It hasn't affected the ride (yet.) Any thoughts? Is this a major problem?

p4nh4ndle

set of tire levers and a patch kit?

I ride a bike

What about a spoke wrench/crank puller/etc?

Bob Dopolina 

Sure. A photo of the bike would help with specific recommendations.

operator

https://www.sheldonbrown.com/creaks.html

It's unfortunate that this is one of your problems as there really is no generic solution. It's basically patience including checking over your entire bike.

First Question: No point recommending any tools. Buy them as you need it to repair your bike.

I ride a bike

From the Specialized web site:

I ride a bike

Thanks, I'm checking that website right now...

Bill Kapaun

A multi tool is designed more to carry with you than replace good home tools.
IF you get one, avoid the cheap ones. You'll screw up too many parts. I don't intend on buying one.

I buy my bike specific tools as I need them.
On some jobs, if the tool outlay is noticeably more than my budget, I may take a part in to the LBS to get serviced. Example, I had to replace a rder cable. I didn't have the $ to invest in a good cable cutter, so I spent $12 total and had them do it. They did a nice job, putting the little crimp thingie on the cable end and I was good to go. I was also able to support them to a small extent.
IF I was replacing cables often, buying the tool would make perfect sense.