A few comments on the early play.
(;ST[2]AP[GOWrite:2.2.21]CA[UTF-8]FF[4]GM[1]SZ[19]KM[0.5]RU[Japanese]PW[Koroviev]FG[259:]PM[0]HA[6]GN[ ]AB[pj][dd][dp][pp][dj][pd]PB[Sku]C[This is an over-the-board game, handicap 6, komi 0.5, Japanese scoring. No particular time-limits (game took around two hours).
Koroviev (white) is 12kyu KGS, Sku is 18/20kyu.
Comments for both sides would be appreciated, but particularly for black - especially general pointers on improvement, strategy etc. We reviewed the game afterwards, and our conclusion is that B tends to:
1) Play too slowly
2) Get bogged down in tactical battles and ignore the bigger picture.
3) Follow the stronger player around, and play too submissively.
We identified many basic mistakes from both sides here, but comments on our general play would be appreciated.
The game was a win for white, but by quite a small margin (3 or 4 points).
NOTE: There are a couple of branches in the game tree - these were just mistakes I made in transcribing the game, before backing up and continuing correctly.]
;W[jj]C[An experimental opening for white, just trying something out with no great plan.
(I did this because in high-handi games I have often found myself wishing I had some stones in the middle to run out to, when the sides get cramped).]
;B[jp]
;W[jd]
;B[jf]C[The right general idea perhaps (splitting white) but we couldn't decide if a more orthodox enclosure (e.g. O16 or similar) would have been better. On the one hand, it builds potential territory, on the other it may be too passive.
*** Good fighting spirit!]
;W[qf]
;B[nc]
;W[rd]
(
;B[ld]C[A mistake by white? R17 seems important here, especially with K16 stone pressuring the black group.
*** Not a bad idea. But it is a little close. See variation.]
;W[qc]
(
;B[pc]C[*** Small. Does not attack White nor does it defend Black. See variation.]
;W[qe]
;B[pe]C[*** Ditto.]
;W[gd]
(
;B[id]C[Would black be better off making an extension around D14, or would that be too passive?
*** Good fighting spirit. However, see variation.]
;W[he]
;B[ie]C[*** Very good.]
(
;W[ec]
(
;B[hc]C[B is aiming here at taking white's base, but perhaps that is unimportant since W already has access to centre?
*** Black is already strong here. See variation.]
;W[dc]
(
;B[ed]C[*** Good fighting spirit. But not so good, tactically. See variation.]
;W[fc]
(
;B[ff]C[Strange move...B said afterwards he was aiming at enclosing White, but I think this is too loose, and B D16 stones need reinforcing first.
*** See variation.]
;W[cd]C[*** Good!]
(
;B[gc]C[*** Just strengthens White and weakens Black. See variation.]
;W[fd]
(
;B[ee]C[Bad for black, we decided later.
*** You are right.]
;W[ce]
;B[fb]C[Wrong time for this move, as white's group is already safe?
*** Yes, small at this point.]
;W[eb]
;B[gb]
;W[ch]C[We looked back at this point after the game and decided that black has come off poorly in the top left, about equal in the top right, and has both territory and maybe influence on the top side. But now he he plays poorly, getting bogged down in the top left and ending up in very bad shape. What was the right move here for black?
*** This is a curious position. Black has some concern about the four stones in the top left, but saving them does nothing else. He would like to attack White's center stone, but White has three ways to come in to the center. The Black stone on the left side may be subject to a pincer. See variations for next.]
(
;B[df]
;W[cf]
;B[dg]
;W[cg]
(
;B[ef]C[*** Very bad. Simply a wasted play. See variation.]
;W[dh]C[Pressuring black's overconentrated shape...]
(
;B[gf]C[*** See variation.]
;W[hf]
(
;B[gg]C[*** Bad shape. See variation.]
;W[hg]
(
;B[eh]C[*** See variation.]
;W[hi]
;B[gh]
;W[hh]
(
;B[ei]C[*** A lot of effort for next to nothing. See variation for better shape.]
(
;W[pf]
(
;B[jh]C[*** Futile attack. See variation.]
;W[ng]C[Since black didn't block, white jumps out.]
;B[ii]
;W[ij]
(
;B[li]C[*** Futile. See variation. End of comments.]
;W[ji]
;B[ih]
;W[kh]
;B[jg]
;W[ki]
;B[hl]
;W[qi]
;B[lh]
;W[pi]
;B[hj]
;W[qj]
;B[ok]
;W[pk]
;B[oj]
;W[pl]
;B[om]
;W[pm]C[Seems bad for black.]
;B[qn]C[W didn't want to block directly at R7 as it seemed like ugly shape, but maybe he should have done?]
;W[ol]
;B[nl]
;W[on]
;B[nm]
;W[pn]
;B[qo]
;W[pq]
;B[qm]
;W[ql]
;B[no]
;W[rm]
;B[rn]
;W[sl]
;B[oi]
;W[oh]
;B[nh]
;W[of]
;B[mi]
;W[oq]
;B[mq]
;W[qq]
;B[op]
;W[qp]
;B[po]
;W[np]
;B[oo]
;W[nq]
;B[mp]
;W[mr]
;B[rp]
;W[rq]
;B[sq]
;W[rr]
;B[sp]
;W[lq]
;B[lp]
;W[kq]
;B[jq]
;W[kp]
;B[ko]
;W[lo]
;B[mo]
;W[cj]
;B[lr]
;W[kr]
;B[jr]
;W[ls]
;B[ln]
;W[dk]
;B[ek]
;W[dl]
;B[el]
;W[dm]
;B[en]
;W[dn]
;B[co]
;W[cn]C[W blocks directly this time.]
;B[bo]
;W[dq]
;B[cq]
;W[pb]
;B[ob]
;W[qa]
;B[kk]
;W[eq]
;B[ep]
;W[fq]
;B[em]
;W[fp]
;B[do]
;W[hr]
;B[ck]
;W[bk]
;B[hq]
;W[gq]
;B[hp]
;W[bn]
;B[go]
;W[cr]
;B[bq]
;W[br]
;B[kg]
;W[fo]
;B[eo]
;W[di]
;B[ej]
;W[me]
;B[ne]
;W[sr]C[mistake by w, thought this was sente to link under...]
;B[ph]
;W[og]
;B[nf]
;W[mg]
;B[lg]
;W[mf]
;B[md]
;W[js]
;B[is]
;W[ks]
;B[ir]
;W[gr]
;B[ns]C[This doesn't work, but it seems worth a try for B.]
;W[nr]
;B[hs]
;W[gs]
;B[ik]C[It was decided in our review after the game that B wasted a lot of moves on this central white group that was clearly already dead]
;W[oa]
;B[na]
;W[pa]
;B[hd]
;W[ge]
;B[ea]
;W[da]
;B[fa]
;W[aq]
;B[ap]
;W[ar]
;B[ao]
;W[an]
;B[gi]
;W[qd]
;B[oe]
;W[sm]
;B[sn]
;W[cc]
;B[le]
;W[lf]
;B[kf]
;W[mh]
;B[ni]
;W[if]
;B[ig]
;W[de]
;B[fe]
;W[fn]
;B[gm]
;W[gn]
;B[hn]
;W[gp]
;B[ho]
;W[fm]
;TW[as:fs][dr:fr][pg:sh][qb:sb][qk:sk][ra:sa][rc:sc][re:sf][ri:sj][rl][sd]B[fl]TB[bp:cp][eg:fg][fh:fi][fj:gj][fk:hk][gl][lo][nd:od][oc][ro:so]
;W[tt]
;B[nn]
;W[tt]
;TW[aa:ca][ab:db][ac:bh][ai:ci][aj:bj][ak][al:cm][as:fs][ck][dr:fr][lr][ms:ss][or:qr][pg:sh][qb:sb][qk:sk][ra:sa][rc:sc][re:sf][ri:sj][rl][sd]B[tt]TB[bp:cp][eg:fg][fh:fi][fj:gj][fk:hk][ga:ma][gl][hb:nb][hm:mm][ic:mc][ij:nj][il:ml][in:kn][io:jo][ip:iq][jd:ke][ji:ki][jk][kh][lk:nk][lo][mn][nd:od][oc][ro:so]
)
(
;B[hj]C[*** You just gotta. Hell or high water, you just gotta. ]
)
)
(
;B[qm]
)
)
(
;W[og]
;B[jh]
)
)
(
;B[fj]C[*** Better shape, but not much better position.]
)
)
(
;B[gh]C[*** Solid.]
)
)
(
;B[fh]
)
)
(
;B[hf]C[*** Connects.]
)
)
(
;B[hf]C[*** Connects and attacks.]
)
)
(
;B[dm]C[*** Perhaps the most usual play. It prevents the pincer, starts a framework, and has some small influence on the center stone.]
)
(
;B[gj]C[*** Protects the Black stone on the left side, attacks the center stone, starts a framework, and has some influence on the Black stones in the top left.]
)
(
;B[eh]C[*** Pretty well saves the Black stones, helps the Black stone on the left side, and attacks the center White stone.]
)
)
(
;B[ce]
;W[de]
;B[df]
;W[ee]
;B[ef]
)
)
(
;B[ce]
;W[de]
;B[bd]
;W[cc]
;B[df]
;W[ee]
;B[ef]
;W[fe]
;B[cf]C[*** Who cares about two stones?]
)
)
(
;B[cd]
)
)
(
;B[cd]
;W[cc]
;B[df]
)
)
(
;B[dc]C[*** Strengthens Black, weakens White, and makes territory in the corner.]
)
)
(
;W[hc]
)
)
(
;B[gf]C[*** Keeping White separated, attacking the group on top and the center stone.]
)
)
(
;B[hd]
)
)
(
;B[hd]C[*** This side is better. Black already has some strength on the right, and the pincer is bigger on this side.]
;W[md]
;B[pf]C[*** Black attacks both White groups.]
;W[pg]
;B[of]
;W[mc]
;B[nb]
;W[mf]
;B[og]
)
)
Black needs to learn some basic shape and tesuji. Also to throw stones away.
Hope you don't find it too displeasing. 
Thanks to Bill and mitsun for the excellent comments, I'll look through these carefully.
Man, Black is gonna be furious when he sees that.