$22: 6-handed, 55 hand, help!

[chipolino]

***** Hand History for Game 2723057124 *****
50/100 Tourney Texas Hold'em Game Table (NL) (Tournament 15796012) - Fri Sep 16 19:02:40 EDT 2005
Table Table 14460 (Real Money) -- Seat 1 is the button
Total number of players : 6
Seat 1: BedSoars (1555)
Seat 2: bob6149 (780)
Seat 3: Win2walkaway (910)
Seat 4: LandShark4U (2045)
Seat 6: afromj (2085)
Seat 8: HERO(625)
bob6149 posts small blind (25)
Win2walkaway posts big blind (50)
** Dealing down cards **
Dealt to HERO [ 5d, 5c ]
LandShark4U folds.
afromj folds.
HERO calls (50)
BedSoars folds.
bob6149 folds.
Win2walkaway checks.
** Dealing Flop ** : [ Ah, Ad, 6c ]
Win2walkaway checks.
HERO bets (80)
Win2walkaway raises (160) to 160
HERO folds.

This is a common situation that I encounter often and don't really know how to play it.
I need comments on everything. That is,

A) should I have folded, limped or raised preflop(blinds go up in 5 hands). If I had only x10BB or less I would have gone all in. But here I don't know how good raising to 150 is since I probably gonna have to put in another big bet on the flop if I get a caller.

B) Since I limped what is my course of action here? Should I have bet the pot when it got checked to me?

Any comments will be appreciated.